NCERT Solutions for Class 7 Maths Chapter 12 Algebraic Expressions Ex 12.1

# NCERT Solutions for Class 7 Maths Chapter 12 Algebraic Expressions Ex 12.1

## NCERT Solutions for Class 7 Maths Chapter 12 Algebraic Expressions Ex 12.1

NCERT Solutions for Class 7 Maths Chapter 12 Algebraic Expressions Ex 12.1 are the part of NCERT Solutions for Class 7 Maths. Here you can find the NCERT Solutions for Class 7 Maths Chapter 12 Algebraic Expressions Ex 12.1.

### Ex 12.1 Class 7 Maths Question 1.

Get the algebraic expressions in the following cases using variables, constants and arithmetic operations:
(i) Subtraction of z from y.
(ii) One half of the sum of numbers x and y.
(iii) The number z multiplied by itself.
(iv) One-fourth of the product of numbers p and q.
(v) Numbers x and y both squared and added.
(vi) Number 5 added to three times the product of number m and n.
(vii) Product of numbers y and z subtracted from 10.
(viii) Sum of numbers a and b subtracted from their product.

Solution:
(i) Subtraction of z from y
Algebraic Expression: y – z

(ii) One half of the sum of numbers x and y
Algebraic Expression: ½ (x + y)

(iii) The number z multiplied by itself.
Algebraic Expression: z × z = z2

(iv) One-fourth of the product of numbers p and q
Algebraic Expression: ¼ pq or pq/4

(v) Numbers x and y both squared and added
Algebraic Expression: x2 + y2

(vi) Number 5 added to three times the product of number m and n
Algebraic Expression: 3mn + 5

(vii) Product of numbers y and z subtracted from 10
Algebraic Expression: 10 – yz

(viii) Sum of numbers a and b subtracted from their product
Algebraic Expression: ab – (a + b) or ab – a – b

### Ex 12.1 Class 7 Maths Question 2.

(i) Identify the terms and their factors in the following expressions. Show the terms and factors by tree diagrams.
(a) x – 3
(b) 1 + x + x2
(c) y – y3
(d) 5xy2 + 7x2y
(e) -ab + 2b2 – 3a2

Solution:

(ii) Identify terms and factors in the expression given below:
(a) -4x + 5
(b) -4x + 5y
(c) 5y + 3y2
(d) xy + 2x2y2
(e) pq + q
(f) 1.2ab – 2.4b + 3.6a
(g) ¾ x + ¼
(h) 0.1p2 + 0.2q2

Solution:

### Ex 12.1 Class 7 Maths Question 3.

Identify the numerical coefficients of terms (other than constants) in the following expressions:
(i) 5 – 3t2
(ii) 1 + t + t2 + t3
(iii) x + 2xy + 3y

(iv) 100m + 1000n
(v) -p2q2 + 7pq
(vi) 1.2 a + 0.8 b
(vii) 3.14 r2
(viii) 2(l + b)
(ix) 0.1 y + 0.01 y2

Solution:

### Ex 12.1 Class 7 Maths Question 4.

(a) Identify terms which contain x and give the coefficient of x.
(i) y2x + y
(ii) 13y2 – 8yx
(iii) x + y + 2
(iv) 5 + z + zx
(v) 1 + x + xy
(vi) 12xy2 + 25
(vii) 7x + xy2

Solution:

(b) Identify terms which contain y2 and give the coefficient of y2.
(i) 8 – xy2
(ii) 5y2 + 7x
(iii) 2x2y – 15xy2 + 7y2

Solution:

### Ex 12.1 Class 7 Maths Question 5.

Classify into monomials, binomials and trinomials:
(i) 4y – 7z
(ii) y2
(iii) x + y – xy
(iv) 100
(v) ab – a – b
(vi) 5 – 3t
(vii) 4p2q – 4pq2
(viii) 7mn
(ix) z2 – 3z + 8
(x) a2 + b2
(xi) z2 + z
(xii) 1 + x + x2

Solution:
(i) 4y – 7z : Binomial
(ii) y2 : Monomial
(iii) x + y – xy : Trinomial
(iv) 100 : Monomial
(v) ab – a – b : Trinomial
(vi) 5 – 3t : Binomial
(vii) 4p2q – 4pq2 : Binomial
(viii) 7mn : Monomial
(ix) z2 – 3z + 8 : Trinomial
(x) a2 + b2 : Binomial
(xi) z2 + z : Binomial
(xii) 1 + x + x2 : Trinomial

### Ex 12.1 Class 7 Maths Question 6.

State whether a given pair of terms is of like or unlike terms.
(i) 1, 100
(ii) -7x, 52x
(iii) -29x, -29y
(iv) 14xy, 42yx
(v) 4m2p, 4mp2
(vi) 12xz, 12 x2y2

Solution:
(i) 1, 100 : Like terms
(ii) -7x, 5/2 x : Like terms
(iii) -29x, -29y : Unlike terms
(iv) 14xy, 42yx : Like terms
(v) 4m2p, 4mp2 : Unlike terms
(vi) 12xz, 12x2z2 : Unlike terms

### Ex 12.1 Class 7 Maths Question 7.

Identify like terms in the following:
(a) -xy2, -4yx2, 8x2, 2xy2, 7y, -11x2, -100x, -11yx, 20x2y, -6x2, y, 2xy, 3x
(b) 10pq, 7p, 8q, -p2q2, -7qp, -100q, -23, 12q2p2, -5p2, 41, 2405p, 78qp, 13p2q, qp2, 701p2

Solution:
(a) Like terms are:
(i) -xy2, 2xy2
(ii) -4yx2, 20x2y
(iii) 8x2, -11x2, -6x2
(iv) 7y, y
(v) -100x, 3x
(vi) -11yx, 2xy

(b) Like terms are:
(i) 10pq, –7qp, 78qp
(ii) 7p, 2405p
(iii) 8q, -100q
(iv) -p2q2, 12q2p2
(v) -23, 41
(vi) -5p2, 701p2
(vii) 13p2q, qp2

You can also like these:

NCERT Solutions for Maths Class 8

NCERT Solutions for Maths Class 9

NCERT Solutions for Maths Class 10

NCERT Solutions for Maths Class 11

NCERT Solutions for Maths Class 12