# CBSE NCERT Solutions for Class 7 Chapter 12

Students get complete and tailored answers for each question in the NCERT textbooks. Answers have been structured in a logical and easy language for quick revisions during examination or tests. NCERT Solutions for Class 7 is a very important resource for students of CBSE Class 7.

**CBSE NCERT Solutions for Class 7 Maths Chapter 12:**

*Question-1*:

Identify like terms in the following:

(a)x y^2, 4yx^2, 8 x^2, 2xy^2, 7y, 11x^2, 100x, 11yx, 20x^2y, 6x^2, y, 2xy, 3x

(b)10pq, 7p, 8q, p^2 q^2, 7qp, 100q, 23, 12q^2p^2, 5p^2, 41, 2405p, 78qp, 13p^2q, qp^2, 701 p^2

*Solution*:

(a) Like terms are:

(i)x y^2 , 2x y^2

(ii) 4 y x^2, 20x^2 y

(iii) 8x^2 , 11x^2, 6x^2

(iv) 7 y, y

(v) 100x, 3x

(vi)11yx, 2xy

(b)

Like terms are:

(i) 10pq, 7pq, 78pq

(ii) 7p, 2405p

(iii) 8q,100q

(iv) p^2 q^2 , 12 p^2 q^2

(v) 12, 41

(vi) 5p^2 ,701 p^2

(vii) 13 p^2 q , q p^2

*Question-2*:

(a) What should be added to x^2 + xy+ y^2 to obtain 2 x^2 + 3xy ?

(b) What should be subtracted from 2a + 8b+ 10 to get 3a + 7b+ 16 ?

*Solution*:

(a) Let p should be added.

Then according to question,

x^2 +xy+ y^2 +p =2 x^2 + 3xy

p =2 x^2 + 3xy - x^2 - xy - y^2

p= x^2- y^2 +2xy

Hence, x^2 -y^2 + 2xy should be added.

(b) Let q should be subtracted.

Then according to question,

2a + 8b+ 10 - q = 3a + 7b+ 16

2a + 8b+ 10 -3a - 7b- 16 = q

-a +b – 6 = q

q = -a +b – 6

*Question-3*:

If p=2, find the value of:

(i) 4p-7

(ii) 3 p^2 +4p-7

(iii) 2p^3 + 3 p^2 -4p -17

*Solution*:

(i) 4p-7=4*2- 7 [Putting p= 2]
= 8 - 7 =1
(ii) 3p^2 +4p-7 =3(2^2) +4(2) -7 [Putting p =2]
= 12+8 -7
= 20 - 7 = 13
(iii) 2 p^3 +3 p^2 -4p -17= 2* 2^3 +3* 2^2 - 4 * 2- 17 [Putting p =2]

=16 +12 - 8 -1 7

= 20 - 17 =3