Page 1
Exercise 2 1 .1
1. Find the common factors of the terms
i. 12x,36
Ans:
Write the factors of each term separately:
12x 2 2 3 x ? ? ? ?
36 2 2 3 3 ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,2,3.
Multiply the common factors, 2 2 3 12 ? ? ?
ii.2y,22xy
Ans:
Write the factors of each term separately:
2y 2 y ??
22xy 2 11 x y ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2, y .
Multiply the common factors, 2 y 2y ?? .
iii.
22
14pq,28p q
Ans:
Write the factors of each term separately:
14pq 2 7 p q ? ? ? ?
22
28p q 2 2 7 p p q q ? ? ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,7,p,q .
Multiply the common factors, 2 7 p q 14pq ? ? ? ? .
iv.
2
2x,3x ,4
Ans:
Page 2
Exercise 2 1 .1
1. Find the common factors of the terms
i. 12x,36
Ans:
Write the factors of each term separately:
12x 2 2 3 x ? ? ? ?
36 2 2 3 3 ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,2,3.
Multiply the common factors, 2 2 3 12 ? ? ?
ii.2y,22xy
Ans:
Write the factors of each term separately:
2y 2 y ??
22xy 2 11 x y ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2, y .
Multiply the common factors, 2 y 2y ?? .
iii.
22
14pq,28p q
Ans:
Write the factors of each term separately:
14pq 2 7 p q ? ? ? ?
22
28p q 2 2 7 p p q q ? ? ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,7,p,q .
Multiply the common factors, 2 7 p q 14pq ? ? ? ? .
iv.
2
2x,3x ,4
Ans:
Write the factors of each term separately:
2x 2 x ??
2
3x 3 x x ? ? ?
4 2 2 ??
The factors that appear in both the lists are the common factors.
Hence, the common factor is 1.
v.
22
6abc,24ab ,12a b
Ans:
Write the factors of each term separately:
6abc 2 3 a b c ? ? ? ? ?
2
24ab 2 2 2 3 a b b ? ? ? ? ? ? ?
2
12a b 2 2 3 a a b ? ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,3,a,b .
Multiply the common factors, 2 3 a b 6ab ? ? ? ? .
vi.
32
16x , 4x ,32x ?
Ans:
Write the factors of each term separately:
3
16x 2 2 2 2 x x x ? ? ? ? ? ? ?
2
4x 1 2 2 x x ? ? ? ? ? ? ?
32x 2 2 2 2 2 x ? ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,2,x
Multiply the common factors, 2 2 x 4x ? ? ?
vii.10pq,20qr,30rp
Ans:
Write the factors of each term separately:
10pq 2 5 p q ? ? ? ?
20qr 2 2 5 q r ? ? ? ? ?
30rp 2 3 5 r p ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,5 .
Multiply the common factors, 2 5 10 ?? .
viii.
2 3 3 2 2 2
3x y ,10x y ,6x y z
Ans:
Page 3
Exercise 2 1 .1
1. Find the common factors of the terms
i. 12x,36
Ans:
Write the factors of each term separately:
12x 2 2 3 x ? ? ? ?
36 2 2 3 3 ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,2,3.
Multiply the common factors, 2 2 3 12 ? ? ?
ii.2y,22xy
Ans:
Write the factors of each term separately:
2y 2 y ??
22xy 2 11 x y ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2, y .
Multiply the common factors, 2 y 2y ?? .
iii.
22
14pq,28p q
Ans:
Write the factors of each term separately:
14pq 2 7 p q ? ? ? ?
22
28p q 2 2 7 p p q q ? ? ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,7,p,q .
Multiply the common factors, 2 7 p q 14pq ? ? ? ? .
iv.
2
2x,3x ,4
Ans:
Write the factors of each term separately:
2x 2 x ??
2
3x 3 x x ? ? ?
4 2 2 ??
The factors that appear in both the lists are the common factors.
Hence, the common factor is 1.
v.
22
6abc,24ab ,12a b
Ans:
Write the factors of each term separately:
6abc 2 3 a b c ? ? ? ? ?
2
24ab 2 2 2 3 a b b ? ? ? ? ? ? ?
2
12a b 2 2 3 a a b ? ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,3,a,b .
Multiply the common factors, 2 3 a b 6ab ? ? ? ? .
vi.
32
16x , 4x ,32x ?
Ans:
Write the factors of each term separately:
3
16x 2 2 2 2 x x x ? ? ? ? ? ? ?
2
4x 1 2 2 x x ? ? ? ? ? ? ?
32x 2 2 2 2 2 x ? ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,2,x
Multiply the common factors, 2 2 x 4x ? ? ?
vii.10pq,20qr,30rp
Ans:
Write the factors of each term separately:
10pq 2 5 p q ? ? ? ?
20qr 2 2 5 q r ? ? ? ? ?
30rp 2 3 5 r p ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,5 .
Multiply the common factors, 2 5 10 ?? .
viii.
2 3 3 2 2 2
3x y ,10x y ,6x y z
Ans:
Write the factors of each term separately:
23
3x y 3 x x y y y ? ? ? ? ? ?
32
10x y 2 5 x x x y y ? ? ? ? ? ? ?
22
6x y z 2 3 x x y y z ? ? ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2 7 p q 14pq ? ? ? ? .
2. Factorise the following expressions
i. 7x 42 ?
Ans:
Take out the common factors from all the terms to factorize.
7x 7 x ??
42 2 3 7 ? ? ?
The common factor is 7
7x 42 (7 x) (2 3 7) 7(x 6) ? ? ? ? ? ? ? ? ?
ii. 6p 12q ?
Ans:
Take out the common factors from all the terms to factorize.
6p 2 3 p ? ? ?
12q 2 2 3 q ? ? ? ?
The common factors are 2 and 3.
6p 12q (2 3 p) (2 2 3 q) ? ? ? ? ? ? ? ?
2 3[p (2 q)] ? ? ? ?
6(p 2q) ??
iii.
2
7a 14a ?
Ans:
Take out the common factors from all the terms to factorize.
2
7a 7 a a ? ? ?
14a 2 7 a ? ? ?
The common factors are 7 and a
2
7a 14a (7 a a) (2 7 a) ? ? ? ? ? ? ? ?
7 a[a 2] ? ? ?
7a(a 2) ??
iv.
3
16z 20z ??
Ans:
Page 4
Exercise 2 1 .1
1. Find the common factors of the terms
i. 12x,36
Ans:
Write the factors of each term separately:
12x 2 2 3 x ? ? ? ?
36 2 2 3 3 ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,2,3.
Multiply the common factors, 2 2 3 12 ? ? ?
ii.2y,22xy
Ans:
Write the factors of each term separately:
2y 2 y ??
22xy 2 11 x y ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2, y .
Multiply the common factors, 2 y 2y ?? .
iii.
22
14pq,28p q
Ans:
Write the factors of each term separately:
14pq 2 7 p q ? ? ? ?
22
28p q 2 2 7 p p q q ? ? ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,7,p,q .
Multiply the common factors, 2 7 p q 14pq ? ? ? ? .
iv.
2
2x,3x ,4
Ans:
Write the factors of each term separately:
2x 2 x ??
2
3x 3 x x ? ? ?
4 2 2 ??
The factors that appear in both the lists are the common factors.
Hence, the common factor is 1.
v.
22
6abc,24ab ,12a b
Ans:
Write the factors of each term separately:
6abc 2 3 a b c ? ? ? ? ?
2
24ab 2 2 2 3 a b b ? ? ? ? ? ? ?
2
12a b 2 2 3 a a b ? ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,3,a,b .
Multiply the common factors, 2 3 a b 6ab ? ? ? ? .
vi.
32
16x , 4x ,32x ?
Ans:
Write the factors of each term separately:
3
16x 2 2 2 2 x x x ? ? ? ? ? ? ?
2
4x 1 2 2 x x ? ? ? ? ? ? ?
32x 2 2 2 2 2 x ? ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,2,x
Multiply the common factors, 2 2 x 4x ? ? ?
vii.10pq,20qr,30rp
Ans:
Write the factors of each term separately:
10pq 2 5 p q ? ? ? ?
20qr 2 2 5 q r ? ? ? ? ?
30rp 2 3 5 r p ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,5 .
Multiply the common factors, 2 5 10 ?? .
viii.
2 3 3 2 2 2
3x y ,10x y ,6x y z
Ans:
Write the factors of each term separately:
23
3x y 3 x x y y y ? ? ? ? ? ?
32
10x y 2 5 x x x y y ? ? ? ? ? ? ?
22
6x y z 2 3 x x y y z ? ? ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2 7 p q 14pq ? ? ? ? .
2. Factorise the following expressions
i. 7x 42 ?
Ans:
Take out the common factors from all the terms to factorize.
7x 7 x ??
42 2 3 7 ? ? ?
The common factor is 7
7x 42 (7 x) (2 3 7) 7(x 6) ? ? ? ? ? ? ? ? ?
ii. 6p 12q ?
Ans:
Take out the common factors from all the terms to factorize.
6p 2 3 p ? ? ?
12q 2 2 3 q ? ? ? ?
The common factors are 2 and 3.
6p 12q (2 3 p) (2 2 3 q) ? ? ? ? ? ? ? ?
2 3[p (2 q)] ? ? ? ?
6(p 2q) ??
iii.
2
7a 14a ?
Ans:
Take out the common factors from all the terms to factorize.
2
7a 7 a a ? ? ?
14a 2 7 a ? ? ?
The common factors are 7 and a
2
7a 14a (7 a a) (2 7 a) ? ? ? ? ? ? ? ?
7 a[a 2] ? ? ?
7a(a 2) ??
iv.
3
16z 20z ??
Ans:
Take out the common factors from all the terms to factorize.
16z 2 2 2 2 z ? ? ? ? ?
3
20z 2 2 5 z z z ? ? ? ? ? ?
The common factors are 2,2, and z .
3
16z 20z (2 2 2 2 z) (2 2 5 z z z) ? ? ? ? ? ? ? ? ? ? ? ? ? ?
(2 2 z)[ (2 2) (5 z z)] ? ? ? ? ? ? ? ?
? ?
2
4z 4 5z ? ? ?
v.
2
20l m 30alm ?
Ans:
Take out the common factors from all the terms to factorize.
2
20l m 2 2 5 1 1 m ? ? ? ? ? ?
30alm 2 3 5 a 1 m ? ? ? ? ? ?
The common factors are 2,5,1, and m .
2
20l m 30alm (2 2 5 1 1 m) (2 3 5 a 1 m) ? ? ? ? ? ? ? ? ? ? ? ? ? ?
(2 5 1 m)[(2 l) (3 a)] ? ? ? ? ? ? ?
10lm(2l 3a) ??
vi.
22
5x y 15xy ?
Ans:
Take out the common factors from all the terms to factorize.
2
5x y 5 x x y ? ? ? ?
2
15xy 3 5 x y y ? ? ? ? ?
The common factors are5,x , and y.
22
5x y 15xy (5 x x y) (3 5 x y y) ? ? ? ? ? ? ? ? ? ?
5 x y[x (3 y)] ? ? ? ? ?
5xy(x 3y) ??
vii.
2 2 2
10a 15b 20c ??
Ans:
Take out the common factors from all the terms to factorize.
2
10a 2 5 a a ? ? ? ?
2
15b 3 5 b b ? ? ? ?
2
20c 2 2 5 c c ? ? ? ? ?
The common factor is 5
2 2 2
10a 15b 20c (2 5 a a) (3 5 b b) (2 2 5 c c) ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
5[(2 a a) (3 b b) (2 2 c c)] ? ? ? ? ? ? ? ? ? ?
Page 5
Exercise 2 1 .1
1. Find the common factors of the terms
i. 12x,36
Ans:
Write the factors of each term separately:
12x 2 2 3 x ? ? ? ?
36 2 2 3 3 ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,2,3.
Multiply the common factors, 2 2 3 12 ? ? ?
ii.2y,22xy
Ans:
Write the factors of each term separately:
2y 2 y ??
22xy 2 11 x y ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2, y .
Multiply the common factors, 2 y 2y ?? .
iii.
22
14pq,28p q
Ans:
Write the factors of each term separately:
14pq 2 7 p q ? ? ? ?
22
28p q 2 2 7 p p q q ? ? ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,7,p,q .
Multiply the common factors, 2 7 p q 14pq ? ? ? ? .
iv.
2
2x,3x ,4
Ans:
Write the factors of each term separately:
2x 2 x ??
2
3x 3 x x ? ? ?
4 2 2 ??
The factors that appear in both the lists are the common factors.
Hence, the common factor is 1.
v.
22
6abc,24ab ,12a b
Ans:
Write the factors of each term separately:
6abc 2 3 a b c ? ? ? ? ?
2
24ab 2 2 2 3 a b b ? ? ? ? ? ? ?
2
12a b 2 2 3 a a b ? ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,3,a,b .
Multiply the common factors, 2 3 a b 6ab ? ? ? ? .
vi.
32
16x , 4x ,32x ?
Ans:
Write the factors of each term separately:
3
16x 2 2 2 2 x x x ? ? ? ? ? ? ?
2
4x 1 2 2 x x ? ? ? ? ? ? ?
32x 2 2 2 2 2 x ? ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,2,x
Multiply the common factors, 2 2 x 4x ? ? ?
vii.10pq,20qr,30rp
Ans:
Write the factors of each term separately:
10pq 2 5 p q ? ? ? ?
20qr 2 2 5 q r ? ? ? ? ?
30rp 2 3 5 r p ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2,5 .
Multiply the common factors, 2 5 10 ?? .
viii.
2 3 3 2 2 2
3x y ,10x y ,6x y z
Ans:
Write the factors of each term separately:
23
3x y 3 x x y y y ? ? ? ? ? ?
32
10x y 2 5 x x x y y ? ? ? ? ? ? ?
22
6x y z 2 3 x x y y z ? ? ? ? ? ? ?
The factors that appear in both the lists are the common factors.
Hence, the common factors are 2 7 p q 14pq ? ? ? ? .
2. Factorise the following expressions
i. 7x 42 ?
Ans:
Take out the common factors from all the terms to factorize.
7x 7 x ??
42 2 3 7 ? ? ?
The common factor is 7
7x 42 (7 x) (2 3 7) 7(x 6) ? ? ? ? ? ? ? ? ?
ii. 6p 12q ?
Ans:
Take out the common factors from all the terms to factorize.
6p 2 3 p ? ? ?
12q 2 2 3 q ? ? ? ?
The common factors are 2 and 3.
6p 12q (2 3 p) (2 2 3 q) ? ? ? ? ? ? ? ?
2 3[p (2 q)] ? ? ? ?
6(p 2q) ??
iii.
2
7a 14a ?
Ans:
Take out the common factors from all the terms to factorize.
2
7a 7 a a ? ? ?
14a 2 7 a ? ? ?
The common factors are 7 and a
2
7a 14a (7 a a) (2 7 a) ? ? ? ? ? ? ? ?
7 a[a 2] ? ? ?
7a(a 2) ??
iv.
3
16z 20z ??
Ans:
Take out the common factors from all the terms to factorize.
16z 2 2 2 2 z ? ? ? ? ?
3
20z 2 2 5 z z z ? ? ? ? ? ?
The common factors are 2,2, and z .
3
16z 20z (2 2 2 2 z) (2 2 5 z z z) ? ? ? ? ? ? ? ? ? ? ? ? ? ?
(2 2 z)[ (2 2) (5 z z)] ? ? ? ? ? ? ? ?
? ?
2
4z 4 5z ? ? ?
v.
2
20l m 30alm ?
Ans:
Take out the common factors from all the terms to factorize.
2
20l m 2 2 5 1 1 m ? ? ? ? ? ?
30alm 2 3 5 a 1 m ? ? ? ? ? ?
The common factors are 2,5,1, and m .
2
20l m 30alm (2 2 5 1 1 m) (2 3 5 a 1 m) ? ? ? ? ? ? ? ? ? ? ? ? ? ?
(2 5 1 m)[(2 l) (3 a)] ? ? ? ? ? ? ?
10lm(2l 3a) ??
vi.
22
5x y 15xy ?
Ans:
Take out the common factors from all the terms to factorize.
2
5x y 5 x x y ? ? ? ?
2
15xy 3 5 x y y ? ? ? ? ?
The common factors are5,x , and y.
22
5x y 15xy (5 x x y) (3 5 x y y) ? ? ? ? ? ? ? ? ? ?
5 x y[x (3 y)] ? ? ? ? ?
5xy(x 3y) ??
vii.
2 2 2
10a 15b 20c ??
Ans:
Take out the common factors from all the terms to factorize.
2
10a 2 5 a a ? ? ? ?
2
15b 3 5 b b ? ? ? ?
2
20c 2 2 5 c c ? ? ? ? ?
The common factor is 5
2 2 2
10a 15b 20c (2 5 a a) (3 5 b b) (2 2 5 c c) ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
5[(2 a a) (3 b b) (2 2 c c)] ? ? ? ? ? ? ? ? ? ?
? ?
222
5 2a 3b 4c ? ? ?
viii.
2
4a 4ab 4ca ? ? ?
Ans:
Take out the common factors from all the terms to factorize.
2
4a 2 2 a a ? ? ? ?
4ab 2 2 a b ? ? ? ?
4ca 2 2 c a ? ? ? ?
The common factors are 2,2, and a
2
4a 4ab 4ca (2 2 a a) (2 2 a b) (2 2 c a) ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
2 2 a[ (a) b c] ? ? ? ? ? ?
4a( a b c) ? ? ? ?
ix.
2 2 2
x yz xy z xyz ??
Ans:
Take out the common factors from all the terms to factorize.
2
x yz x x y z ? ? ? ?
2
xy z x y y z ? ? ? ?
2
xyz x y z z ? ? ? ?
The common factors are x,y , and z
2 2 2
x yz xy z xyz (x x y z) (x y y z) (x y z z) ? ? ? ? ? ? ? ? ? ? ? ? ? ?
x y z[x y z] ? ? ? ? ?
xyz(x y z) ? ? ?
x.
22
ax y bxy cxyz ??
Ans:
Take out the common factors from all the terms to factorize.
2
ax y a x x y ? ? ? ?
2
bxy b x y y ? ? ? ?
cxyz c x y z ? ? ? ?
The common factors are x and y.
22
ax y bxy cxyz (a x x y) (b x y y) (c x y z) ? ? ? ? ? ? ? ? ? ? ? ? ? ?
(x y)[(a x) (b y) (c z)] ? ? ? ? ? ? ?
xy(ax by cz) ? ? ?
3. Factorise
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