Rd Sharma 2021 Solutions for Class 9 Maths Chapter 5 Factorization Of Algebraic Expressions are provided here with simple step-by-step explanations. These solutions for Factorization Of Algebraic Expressions are extremely popular among Class 9 students for Maths Factorization Of Algebraic Expressions Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Rd Sharma 2021 Book of Class 9 Maths Chapter 5 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Rd Sharma 2021 Solutions. All Rd Sharma 2021 Solutions for class Class 9 Maths are prepared by experts and are 100% accurate.
Page No 5.14:
Question 1:
Factorize each of the following expressions:
p3 + 27
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula for sum of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 2:
y3 + 125
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula for sum of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 3:
1 − 27a3
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula for difference of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 4:
8x3y3 + 27a3
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula for sum of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 5:
64a3 − b3
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula for difference of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 6:
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula for difference of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 7:
10x4y − 10xy4
Answer:
The given expression to be factorized is
Take common from the two terms,. Then we have
This can be written in the form
Recall the formula for difference of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 8:
54x6y + 2x3y4
Answer:
The given expression to be factorized is
Take common from the two terms,. Then we have
This can be written in the form
Recall the formula for sum of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 9:
32a3 + 108b3
Answer:
The given expression to be factorized is
Take common from the two terms,. Then we have
This can be written in the form
Recall the formula for sum of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 10:
(a − 2b)3 − 512b3
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula for difference of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 11:
8x2y3 − x5
Answer:
The given expression to be factorized is
Take common. Then we have
This can be written as
Recall the formula for difference of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 12:
1029 − 3x3
Answer:
The given expression to be factorized is
Take common 3. Then we have from the above expression,
This can be written as
Recall the formula for difference of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 13:
x3y3 + 1
Answer:
The given expression to be factorized is
This can be written as
Recall the formula for sum of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 14:
x4y4 − xy
Answer:
The given expression to be factorized is
Take common. Then we have from the above expression,
This can be written as
Recall the formula for difference of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 15:
a3 + b3 + a + b
Answer:
The given expression to be factorized is
This can be written as
=
Recall the formula for sum of two cubes
Using the above formula, we have
Take common. Then we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 16:
Simplify:
(i)
(ii)
(iii)
Answer:
(i) The given expression is
Assumeand. Then the given expression can be rewritten as
Recall the formula for sum of two cubes
Using the above formula, the expression becomes
Note that both and b are positive. So, neithernor any factor of it can be zero.
Therefore we can cancel the termfrom both numerator and denominator. Then the expression becomes
(ii) The given expression is
Assumeand. Then the given expression can be rewritten as
Recall the formula for difference of two cubes
Using the above formula, the expression becomes
Note that both, b is positive and unequal. So, neithernor any factor of it can be zero.
Therefore we can cancel the termfrom both numerator and denominator. Then the expression becomes
(iii) The given expression is
Assumeand. Then the given expression can be rewritten as
Recall the formula for difference of two cubes
Using the above formula, the expression becomes
Note that both, b is positive and unequal. So, neithernor any factor of it can be zero.
Therefore we can cancel the termfrom both numerator and denominator. Then the expression becomes
Page No 5.14:
Question 17:
(a + b)3 − 8(a − b)3
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula for difference of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 18:
(x + 2)3 + (x − 2)3
Answer:
The given expression to be factorized is
Recall the formula for sum of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 19:
x6 + y6
Answer:
The given expression to be factorized is
This can be written as
Recall the formula for sum of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 20:
a12+ b12
Answer:
The given expression to be factorized is
This can be written as
Recall the formula for difference of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 21:
x3 + 6x2 + 12x + 16
Answer:
The given expression to be factorized is
This can be written as
Take common x2 from first two terms, 2x from the next two terms andfrom the last two terms. Then we have,
Finally, take common. Then we get,
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 22:
Answer:
The given expression to be factorized is
This can be written as
Recall the formula for sum of two cubes
Using the above formula and taking common from the last two terms, we get
Take common. Then we have,
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 23:
a3 + 3a2b + 3ab2 + b3 − 8
Answer:
The given expression to be factorized is
Recall the well known formula
The given expression can be written as
Recall the formula for difference of two cubes
Using the above formula and taking common –2 from the last two terms, we get
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.14:
Question 24:
8a3 − b3 − 4ax + 2bx
Answer:
The given expression to be factorized is
The given expression can be written as
Recall the formula for difference of two cubes
Using the above formula and taking common from the last two terms, we get
Take common. Then we have,
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.17:
Question 1:
Factorize:
64a3 + 125b3 + 240a2b + 300ab2
Answer:
The given expression to be factorized is
This can be written in the form
Take common from the last two terms,
This can be written in the following form
Recall the formula for the cube of the sum of two numbers
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.17:
Question 2:
125x3 − 27y3 − 225x2y + 135xy2
Answer:
The given expression to be factorized is
This can be written in the form
Take common from the last two terms,. Then we get
This can be written in the following form
Recall the formula for the cube of the difference of two numbers
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is of is.
Page No 5.17:
Question 3:
Answer:
The given expression to be factorized is
This can be written in the form
Take common from the last two terms,. Then we get
This can be written in the following form
Recall the formula for the cube of the sum of two numbers
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is of is.
Page No 5.17:
Question 4:
8x3 + 27y3 + 36x2y + 54xy2
Answer:
The given expression to be factorized is
This can be written in the form
Take common from the last two terms. Then we get
This can be written in the following form
Recall the formula for the cube of the sum of two numbers
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is of is.
Page No 5.17:
Question 5:
a3 − 3a2b + 3ab2 − b3 + 8
Answer:
The given expression to be factorized is
This can be written in the form
Take common from the third and fourth terms. Then we get
This can be written in the following form
Recall the formula for the cube of the difference of two numbers
Using the above formula, we have
This can be written in the following form
Recall the formula for the sum of two cubes
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is ofis.
Page No 5.17:
Question 6:
x3 + 8y3 + 6x2y + 12xy2
Answer:
The given expression to be factorized is
This can be written in the form
Take common from the last two terms. Then we get
This can be written in the following form
Recall the formula for the cube of the sum of two numbers
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is of is.
Page No 5.18:
Question 7:
8x3 + y3 + 12x2y + 6xy2
Answer:
The given expression to be factorized is
This can be written in the form
Take common 6xy from the last two terms,. Then we get
This can be written in the following form
Recall the formula for the cube of the sum of two numbers
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is of is.
Page No 5.18:
Question 8:
8a3 + 27b3 + 36a2b + 54ab2
Answer:
The given expression to be factorized is
This can be written in the form
Take common from the last two terms,. Then we get
This can be written in the following form
Recall the formula for the cube of the sum of two numbers
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is of is.
Page No 5.18:
Question 9:
8a3 − 27b3 − 36a2b + 54ab2
Answer:
The given expression to be factorized is
This can be written in the form
Take common – 18ab from the last two terms,. Then we get
This can be written in the following form
Recall the formula for the cube of the difference of two numbers
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is ofis.
Page No 5.18:
Question 10:
x3 − 12x(x − 4) − 64
Answer:
The given expression to be factorized is
This can be written in the form
Take common – 12x from the last two terms,. Then we get
This can be written in the following form
Recall the formula for the cube of the difference of two numbers
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is of is.
Page No 5.18:
Question 11:
a3x3 − 3a2bx2 + 3ab2x − b3
Answer:
The given expression to be factorized is
This can be written in the form
Take common from the last two terms,. Then we get
This can be written in the following form
Recall the formula for the cube of the difference of two numbers
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is of is.
Page No 5.23:
Question 1:
Factorize each of the following expressions:
a3 + 8b3 + 64c3 − 24abc
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.23:
Question 2:
x3 − 8y3 + 27z3 + 18xyz
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is ofis.
Page No 5.23:
Question 3:
27x3 − y3 − z3 − 9xyz
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is of is .
Page No 5.23:
Question 4:
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is ofis .
Page No 5.24:
Question 5:
8x3 +27y3 − 216z3 + 108xyz
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is ofis .
Page No 5.24:
Question 6:
125 + 8x3 − 27y3 + 90xy
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is ofis .
Page No 5.24:
Question 7:
8x3 − 125y3 + 180xy + 216
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is ofis .
Page No 5.24:
Question 8:
Multiply:
(i) x2 + y2 + z2 − xy + xz + yz by x + y − z
(ii) x2 + 4y2 + z3 + 2xy + xz − 2yz by x − 2y − z
(iii) x2 + 4y2 + 2xy − 3x + 6y + 9 by x − 2y + 3
(iv) 9x2 + 25y2 + 15xy + 12x − 20y + 16 by 3x − 5y + 4
(v) x2 + 4y2 + z2 + 2xy + xz – 2yz by (−z + x – 2y)
Answer:
(v) x2 + 4y2 + z2 + 2xy + xz – 2yz by (−z + x – 2y)
Hence, the required value is
Page No 5.24:
Question 9:
(3x − 2y)3 + (2y − 4z)3 + (4z − 3x)3
Answer:
The given expression to be factorized is
Let, and. Then the given expression becomes
Note that
Recall the formula
When, this becomes
So, we have the new formula
,
when.
Using the above formula, the given expression can be written as
Put, and. Then we have
We cannot further factorize the expression.
So, the required factorization is ofis.
Page No 5.24:
Question 10:
(2x − 3y)3 + (4z − 2x)3 + (3y − 4z)3
Answer:
The given expression to be factorized is
Let, and. Then the given expression becomes
Note that
Recall the formula
When, this becomes
So, we have the new formula
, when.
Using the above formula, the given expression can be written as
Put, and. Then we have
We cannot further factorize the expression.
So, the required factorization is ofis .
Page No 5.24:
Question 11:
Answer:
The given expression to be factorized is
Let, and. Then the given expression becomes
Note that
Recall the formula
When, this becomes
So, we have the new formula
, when.
Using the above formula, the given expression can be written as
Put, and.
Then we have
We cannot further factorize the expression.
So, the required factorization is of is
Page No 5.24:
Question 12:
(a − 3b)3 + (3b − c)3 + (c − a)3
Answer:
The given expression to be factorized is
Let, and. Then the given expression becomes
Note that
Recall the formula
When, this becomes
So, we have the new formula
, when.
Using the above formula, the given expression can be written as
Put, and. Then we have
We cannot further factorize the expression.
So, the required factorization is ofis.
Page No 5.24:
Question 13:
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is of is .
Page No 5.24:
Question 14:
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is of is.
Page No 5.24:
Question 15:
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula
Using the above formula, we have
We cannot further factorize the expression.
So, the required factorization is of is .
Page No 5.24:
Question 16:
(x – 2y)3 + (2y – 3z)3 + (3z – x)3
Answer:
Page No 5.24:
Question 17:
Find the value of x3 + y3 − 12xy + 64, when x + y =−4
Answer:
The given expression is
It is given that
The given expression can be written in the form
Recall the formula
Using the above formula, we have
Page No 5.24:
Question 18:
If a, b, c are all non-zero and a + b + c = 0, prove that .
Answer:
Page No 5.25:
Question 1:
The factors of x3 −x2y − xy2 + y3 are
(a)(x + y) (x2 − xy + y2)
(b) (x + y) (x2 + xy + y2)
(c) (x + y)2 (x − y)
(d) (x − y)2 (x + y)
Answer:
The given expression to be factorized is
Take common from the first two terms and from the last two terms. That is
Finally, take commonfrom the two terms. That is
So, the correct choice is (d).
Page No 5.25:
Question 2:
The factors of x3 − 1 + y3 + 3xy are
(a) (x − 1 + y) (x2 + 1 + y2 + x + y − xy)
(b) (x + y + 1) (x2 + y2 + 1 −xy − x − y)
(c) (x − 1 + y) (x2 − 1 − y2 + x + y + xy)
(d) 3(x + y −1) (x2 + y2 − 1)
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula
Using the above formula, we have
So, the correct choice is (a).
Page No 5.25:
Question 3:
The factors of 8a3 + b3 − 6ab + 1 are
(a) (2a + b − 1) (4a2 + b2 + 1 − 3ab − 2a)
(b) (2a − b + 1) (4a2 + b2 − 4ab + 1 − 2a + b)
(c) (2a + b + 1) (4a2 + b2 + 1 −2ab − b − 2a)
(d) (2a − 1 + b) (4a2 + 1 − 4a − b − 2ab)
Answer:
The given expression to be factorized is
This can be written in the form
Recall the formula
Using the above formula, we have
So, the correct choice is (c).
Page No 5.25:
Question 4:
(x + y)3 − (x − y)3 can be factorized as
(a) 2y (3x2 + y2)
(b) 2x (3x2 + y2)
(c) 2y (3y2 + x2)
(d) 2x (x2+ 3y2)
Answer:
The given expression to be factorized is
Recall the formula for difference of two cubes
Using the above formula, we have,
So, the correct choice is (a).
Page No 5.25:
Question 5:
The expression (a − b)3 + (b − c)3 + (c −a)3 can be factorized as
(a) (a − b) (b − c) (c −a)
(b) 3(a − b) (b − c) (c −a)
(c) −3(a − b) (b −c) (c − a)
(d) (a + b + c) (a2 + b2 + c2 − ab − bc − ca)
Answer:
The given expression is
Let, and. Then the given expression becomes
Note that:
Recall the formula
When, this becomes
So, we have the new formula
, when.
Using the above formula, the value of the given expression is
So, the correct choice is (b).
Page No 5.26:
Question 6:
The value of
(a) 2
(b) 3
(c) 2.327
(d) 2.273
Answer:
The given expression is
This can be written in the form
Assumeand. Then the given expression can be rewritten as
Recall the formula for difference of two cubes
Using the above formula, the expression becomes
Note that both a and b are positive, unequal. So, neithernor any factor of it can be zero.
Therefore we can cancel the termfrom both numerator and denominator. Then the expression becomes
So, the correct choice is (a).
Page No 5.26:
Question 7:
The value of is
(a) 0.006
(b) 0.02
(c) 0.0091
(d) 0.00185
Answer:
The given expression is
Assumeand. Then the given expression can be rewritten as
Recall the formula for sum of two cubes
Using the above formula, the expression becomes
Note that both and b are positive. So, neithernor any factor of it can be zero.
Therefore we can cancel the termfrom both numerator and denominator. Then the expression becomes
So, the correct choice is (b).
Page No 5.26:
Question 8:
Mark the correct alternative in each of the following:
The factors of a2 − 1 − 2x − x2 are
(a) (a − x + 1) (a − x − 1)
(b) (a + x − 1) (a − x + 1)
(c) (a + x +1) (a − x + 1)
(d) none of these
Answer:
The given expression to be factorized is
Take commonfrom the last three terms and then we have
So, the correct choice is (c).
Page No 5.26:
Question 9:
The factors of x4 + x2 + 25 are
(a) (x2 + 3x + 5) (x2 − 3x + 5)
(b) (x2 + 3x + 5) (x2 + 3x − 5)
(c) (x2 + x +5) (x2 − x + 5)
(d) none of these
Answer:
The given expression to be factorized is
This can be written in the form
So, the correct choice is (a).
Page No 5.26:
Question 10:
The factors of x2 + 4y2 + 4y − 4xy − 2x − 8 are
(a) (x − 2y −4) (x − 2y + 2)
(b) (x − y + 2) (x − 4y − 4)
(c) (x + 2y − 4) (x + 2y + 2)
(d) none of these
Answer:
The given expression to be factorized is
This can be arrange in the form
Let. Then the above expression becomes
Put.
So, the correct choice is (a).
Page No 5.26:
Question 11:
The factors of x3 − 7x + 6 are
(a) x (x − 6) (x − 1)
(b) (x2 − 6) (x − 1)
(c) (x + 1) (x + 2) (x + 3)
(d) (x − 1) (x + 3) (x − 2)
Answer:
The given expression to be factorized is
This can be written in the form
Take common x from the first two terms andfrom the last two terms. Then we have
Finally, take commonfrom the above expression,
So, the correct choice is (d).
Page No 5.26:
Question 12:
The expression x4 + 4 can be factorized as
(a) (x2 + 2x + 2) (x2 − 2x + 2)
(b) (x2 + 2x + 2) (x2 + 2x − 2)
(c) (x2 − 2x − 2) (x2 − 2x + 2)
(d) (x2 + 2) (x2 − 2)
Answer:
The given expression to be factorized is
This can be written in the form
So, the correct choice is (a).
Page No 5.26:
Question 13:
If 3x = a + b + c, then the value of (x − a)3 + (x −b)3 + (x − c)3 − 3(x − a) (x − b) (x −c) is
(a) a + b + c
(b) (a − b) (b − c) (c − a)
(c) 0
(d) none of these
Answer:
The given expression is
Recall the formula
Using the above formula the given expression becomes
Given that
Therefore the value of the given expression is
So, the correct choice is (c).
Page No 5.26:
Question 14:
If (x + y)3 − (x − y)3 − 6y(x2 − y2) = ky3, then k =
(a) 1
(b) 2
(c) 4
(d) 8
Answer:
The given equation is
Recall the formula
Using the above formula, we have
, provided.
So, the correct choice is (d).
Page No 5.26:
Question 15:
If x3 − 3x2 + 3x − 7 = (x + 1) (ax2 + bx + c), then a + b + c =
(a) 4
(b) 12
(c) −10
(d) 3
Answer:
The given equation is
x3 − 3x2 + 3x − 7 = (x + 1) (ax2 + bx + c)
This can be written as
Comparing the coefficients on both sides of the equation.
We get,
c = -7 .......(4)
Putting the value of a from (1) in (2)
We get,
So the value of a, b and c is 1, – 4 and -7 respectively.
Therefore,
a + b + c =1 - 4 - 7 = -10
So, the correct choice is (c).
Page No 5.27:
Question 1:
The factorized form of the expression y2 + (x – 1)y – x is ____________.
Answer:
Hence, the factorized form of the expression y2 + (x – 1)y – x is (y ​– 1)(y + x).
Page No 5.27:
Question 2:
The factorized form of a3 + (b – a)3 – b3 is ____________.
Answer:
Hence, the factorized form of a3 + (b – a)3 – b3 is 3ab(a – b).
Page No 5.27:
Question 3:
If
Answer:
Hence, if
Page No 5.27:
Question 4:
Factorization of the polynomial gives ____________.
Answer:
Hence, factorization of the polynomial gives .
Page No 5.27:
Question 5:
The polynomial x2 + y2 – z2 – 2xy on factorization gives _____________.
Answer:
Hence, the polynomial x2 + y2 – z2 – 2xy on factorization gives .
Page No 5.27:
Question 6:
The factors of the expression are ____________.
Answer:
Hence, the factors of the expression are .
Page No 5.27:
Question 7:
The polynomial , x6 + 64y6 on factorization gives _____________.
Answer:
Hence, the polynomial x6 + 64y6 on factorization gives .
Page No 5.27:
Question 8:
The factorization form of a4 + b4 – a2b2 is _____________.
Answer:
Hence, the factorization form of a4 + b4 – a2b2 is .
Page No 5.27:
Question 9:
If , then the value of is ____________.
Answer:
Hence, the value of is 1090.
Page No 5.27:
Question 10:
The factorized form of is _____________.
Answer:
Hence, the factorized form of is
Page No 5.27:
Question 11:
The factorized form of a3 + b3 + 3ab – 1 is ____________.
Answer:
Hence, the factorized form of a3 + b3 + 3ab – 1 is
Page No 5.27:
Question 1:
If a + b + c = 0, then write the value of a3 + b3 + c3.
Answer:
Recall the formula
When, we have
Page No 5.27:
Question 2:
If a2 + b2 + c2 = 20 and a + b + c = 0, find ab + bc + ca.
Answer:
Recall the formula
Given that
Then we have
Page No 5.27:
Question 3:
If a + b + c = 9 and ab + bc + ca = 40, find a2 + b2 +c2.
Answer:
Recall the formula
Given that
,
Then we have
Page No 5.27:
Question 4:
If a2 + b2 + c2 = 250 and ab + bc + ca = 3, find a + b + c.
Answer:
Recall the formula
Given that
,
Then we have
Page No 5.27:
Question 5:
Write the value of 253 − 753 + 503.
Answer:
The given expression is
Let, and. Then the given expression becomes
Note that
Recall the formula
When, this becomes
So, we have the new formula
, when.
Using the above formula, the value of the given expression is
Page No 5.27:
Question 6:
Write the value of 483 − 303 − 183.
Answer:
The given expression is
Let, and. Then the given expression becomes
Note that
Recall the formula
When, this becomes
So, we have the new formula
, when.
Using the above formula, the value of the given expression is
Page No 5.28:
Question 7:
Write the value of
Answer:
The given expression is
Let, and. Then the given expression becomes
Note that:
Recall the formula
When, this becomes
So, we have the new formula
, when.
Using the above formula, the value of the given expression is
Page No 5.28:
Question 8:
Write the value of 303 + 203 − 503.
Answer:
The given expression is
Let, and. Then the given expression becomes
Note that
Recall the formula
When, this becomes
So, we have the new formula
, when.
Using the above formula, the value of the given expression is
Page No 5.28:
Question 9:
Factorize: x4 + x2 + 25.
Answer:
The given expression to be factorized is
This can be written in the form
We cannot further factorize the expression.
So, the required factorization is.
Page No 5.28:
Question 10:
Factorize : x2 − 1 − 2a − a2
Answer:
The given expression to be factorized is
Take commonfrom the last three terms and then we have
We cannot further factorize the expression.
So, the required factorization is.
Page No 5.9:
Question 1:
Factorize:
1.
Answer:
The given expression to be factorized is
Take common x from the first two terms and -3 from the last two terms. That is
Finally, take common x2 + 1from the two terms. That is
We cannot further factorize the expression.
So, the required factorization is.
Page No 5.9:
Question 2:
Factorize:
2. a(a+b)3 − 3a2b (a + b)
Answer:
The given expression to be factorized is
Take common from the two terms. That is
Expand the term within the second braces.
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 3:
Answer:
The given expression to be factorized is
We know that
The given expression then becomes
Take common from the two terms. That is
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 4:
Factorize:
a2x2 + (ax2 + 1)x + a
Answer:
The given expression to be factorized is
Simplify the middle term. That is
Take common from the first two terms and 1 from the last two terms. That is
Finally, take commonfrom the two terms. That is
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 5:
Factorize:
x2 + y − xy − x
Answer:
The given expression to be factorized is
Rearrange the given expression as
Take common x from the first two terms and -1 from the last two terms. That is
Finally, take commonfrom the two terms. That is
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 6:
Factorize:
x3 − 2x2y + 3xy2 − 6y3
Answer:
The given expression to be factorized is
Take common from the first two terms and from the last two terms. That is
Finally, take commonfrom the two terms. That is
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 7:
Factorize:
6ab − b2 + 12ac − 2bc
Answer:
The given expression to be factorized is
Take common b from the first two terms and from the last two terms. That is
Finally, take commonfrom the two terms. That is
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 8:
Factorize:
Answer:
The given expression to be factorized is
Take common 4 from the last two terms. That is
Again take commonfrom the two terms of the above expression.
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 9:
Factorize:
(a − b + c)2 + (b − c + a)2 + 2(a − b + c) (b − c + a)
Answer:
The given expression to be factorized is
This can be written as
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 10:
Factorize:
a2 + 2ab +b2 − c2
Answer:
The given expression to be factorized is
This can be arrange in the form
Substitutingin the above expression, we get.
Put.
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 11:
Factorize:
a2 + 4b2 − 4ab − 4c2
Answer:
The given expression to be factorized is
This can be arrange in the form
Substitute.
Put.
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 12:
Factorize:
x2 − y2 − 4xz + 4z2
Answer:
The given expression to be factorized is
Rearrange the terms as
Substitutingin the avove expression,
Put.
We cannot further factorize the expression.
So, the required factorization ofis.
Page No 5.9:
Question 13:
Factorize:
Answer:
The given expression to be factorized is
This can be written in the form
Take common x from the first two terms andfrom the last two terms,
Finally take commonfrom the above expression,
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 14:
Factorize:
Answer:
The given expression to be factorized is
This can be written in the form
Take common x from the first two terms andfrom the last two terms,
Finally take commonfrom the above expression,
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 15:
Factorize:
Answer:
The given expression to be factorized is
This can be written in the form
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 16:
Give possible expressions for the length and breadth of the rectangle having 35y2 + 13y − 12 as its area.
Answer:
The area of the rectangle is
First we will factorize the above expression. This can be written in the form
Take commonfrom the first two terms andfrom the last two terms,
Finally take commonfrom the above expression,
The area of a rectangle having length a and breadth bis ab.
Here we don’t know the bigger or the smaller factor. So, the two possibilities are
(i) Length isand breadth is
(ii) Length is and breadth is
Page No 5.9:
Question 17:
What are the possible expressions for the dimensions of the cuboid whose volume is 3x2− 12x.
Answer:
The volume of the cuboid is
First we will factorize the above expression.
Take commonfrom the two terms of the above expression,
The volume of a cuboid having length, breadth b and height is.
Here the word ‘dimensions’ stands for the length, breadth and height of the cuboid. So, the three possibilities are
(i) Length is, breadth is x and height is
(ii) Length is x , breadth isand height is
(iii) Length is, breadth isand height is x
There are many other possibilities also, because we can consider the product of two simple factors as a single factor.
Page No 5.9:
Question 18:
Factorize:
Answer:
The given expression to be factorized is
We have
Use the above result in the original expression to get
Substituting in the above , we get
Put.
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 19:
Factorize:
(x+2) (x2+25) − 10x2 − 20x
Answer:
The given expression to be factorized is
Take common from the last two terms. That is
Again take commonfrom the two terms of the above expression. Then
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 20:
Factorize:
Answer:
The given expression to be factorized is
This can be written in the form
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 21:
Factorize:
a2 + b2 + 2(ab + bc + ca)
Answer:
The given expression to be factorized is
This can be written as
Take commonfrom the last two terms.
Finally, take common from the two terms of the above expression.
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 22:
Factorize:
4(x − y)2 − 12(x − y) (x + y) + 9(x + y)2
Answer:
The given expression to be factorized is
Substituting andin the above expression, we get
=
This can be arrange in the form
Putand.
Take common -1 from the expression within the braces.
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 23:
Factorize:
a2 + b2 + 2bc − c2
Answer:
The given expression to be factorized is
This can be arrange in the form
Substitutingin the above expression, we get.
Put.
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 24:
Factorize:
xy9 − yx9
Answer:
The given expression to be factorized is
This can be written in the form
Take commonfrom the two terms of the above expression
We cannot further factorize the expression.
So, the required factorization of is
Page No 5.9:
Question 25:
Factorize:
x4 + x2y2 + y4
Answer:
The given expression to be factorized is
Add and subtract the termin the given expression.
Substitutingin the above expression, we get
Putin the above expression,
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 26:
Factorize:
Answer:
The given expression to be factorized is
This can be written in the form
Take common x from the first two terms andfrom the last two terms.
Finally, take commonfrom the above expression. Then we have
We cannot further factorize the expression.
So, the required factorization is.
Page No 5.9:
Question 27:
Factorize:
Answer:
The given expression to be factorized is
This can be written in the form
Take common x from the first two terms andfrom the last two terms,
Finally take commonfrom the above expression,
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 28:
Factorize:
Answer:
The given expression to be factorized is
This can be written in the form
Take common x from the first two terms andfrom the last two terms. Then we have
Finally take commonfrom the above expression. Then we have
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 29:
Factorize:
Answer:
The given expression to be factorized is
This can be written in the form
Take common x from the first two terms andfrom the last two terms. Then we have
Finally take commonfrom the above expression,
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 30:
Factorize:
Answer:
The given expression to be factorized is
This can be written in the form
Take common x from the first two terms andfrom the last two terms,
Finally take commonfrom the above expression,
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 31:
Factorize:
Answer:
The given expression to be factorized is
This can be written in the form
Take commonfrom the first two terms andfrom the last two terms,
Finally take commonfrom the above expression,
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 32:
Factorize:
Answer:
The given expression to be factorized is
This can be written in the form
Take commonfrom the first two terms andfrom the last two terms,
Finally take commonfrom the above expression,
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 33:
Factorize:
9(2a − b)2 − 4(2a − b) − 13
Answer:
The given expression to be factorized is
Substitutingin the above expression, we get
This can be written in the form
Take common x from the first two terms and 1 from the last two terms,
Finally take commonfrom the above expression,
Put,
We cannot further factorize the expression.
So, the required factorization ofis.
Page No 5.9:
Question 34:
Factorize:
7(x − 2y)2 − 25(x − 2y) + 12
Answer:
The given expression to be factorized is
Substitutingin the above expression, we get
This can be written in the form
Take commonfrom the first two terms andfrom the last two terms,
Finally take commonfrom the above expression,
Put in the above expression,
We cannot further factorize the expression.
So, the required factorization of is.
Page No 5.9:
Question 35:
Factorize:
2(x + y)2 − 9(x + y) − 5
Answer:
The given expression to be factorized is
Substitutingin the above expression, we get
This can be written in the form
Take commonfrom the first two terms andfrom the last two terms,
Finally take commonfrom the above expression,
Put. Then we have
We cannot further factorize the expression.
So, the required factorization of is.
View NCERT Solutions for all chapters of Class 9