NCERT Solutions for class 8 Maths Chapter 9 Algebraic Expressions and Identities Exercise 9.1

The NCERT solutions for Class 8 CBSE enhance topics with frequent, focused, engaging math challenges and activities that strengthen math concepts. Each question of the exercise has been carefully solved and you get the correct answer.

Class 8 Maths Chapter 9 Algebraic Expressions and Identities Exercise 9.1 questions and answers helps students to understand polynomial’s terms, factors and coefficients as well as addition and subtraction of the polynomials. NCERT Solutions for Class 8 Maths Chapter 9 Algebraic Expressions and Identities exercise 9.1 are prepared by BYJU’S subject experts using step by step approach. Download free NCERT Solutions for Maths Chapter 9 and practice offline.

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NCERT Solutions CBSE Class 8 Maths Chapter 9 Algebraic Expressions and Identities Exercise 9.1 Part 1
NCERT Solutions CBSE Class 8 Maths Chapter 9 Algebraic Expressions and Identities Exercise 9.1 Part 2
NCERT Solutions CBSE Class 8 Maths Chapter 9 Algebraic Expressions and Identities Exercise 9.1 Part 3

 

Access Answers of Maths NCERT class 8 Chapter 9 Algebraic Expressions and Identities Exercise 9.1 Page number 140

 

Exercise 9.1 Page No: 140

  1. Identify the terms, their coefficients for each of the following expressions.
    (i) 5xyz2 – 3zy
     (ii) 1 + x + x2
    (iii) 4x2y2 – 4x2y2z2 + z2
     (iv) 3 – pq + qr – p
     (v) (x/2) + (y/2) – xy
     (vi) 0.3a – 0.6ab + 0.5b

Solution :

Sl. No.

Expression

Term

Coefficient

i)

5xyz2 – 3zy

Term: 5xyz2 

Term: -3zy

5
-3

ii)

1 + x + x2

Term: 1
Term: x
Term x2

1
1
1

iii)

4x2y2 – 4x2y2z2 + z2

Term: 4x2y2
Term: -4 x2y2z2
Term :  z2

4
-4
1

iv)

3 – pq + qr – p

3
-pq
qr
-p

3
-1
1
-1

v)

(x/2) + (y/2) – xy

x/2
Y/2
-xy

½
1/2
-1

vi)

0.3a – 0.6ab + 0.5b

0.3a
-0.6ab
0.5b

0.3
-0.6
0.5

2. Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories?
x + y, 1000, x + x2 + x3 + x4 , 7 + y + 5x, 2y – 3y2 , 2y – 3y2 + 4y3 , 5x – 4y + 3xy, 4z – 15z2 , ab + bc + cd + da, pqr, p2q + pq2 , 2p + 2q

Solution:

Let us first define the classifications of these 3 polynomials:

Monomials, Contain only one term.

Binomials, Contain only two terms.

Trinomials, Contain only three terms.

x + y

two terms

Binomial

1000

one term

Monomial

x + x2 + x3 + x4

four terms

Polynomial, and it does not fit in listed three categories

2y – 3y2

two terms

Binomial

2y – 3y2 + 4y3

three terms

Trinomial

5x – 4y + 3xy

three terms

Trinomial

4z – 15z2

two terms

Binomial

ab + bc + cd + da

four terms

Polynomial, and it does not fit in listed three categories

pqr

one term

Monomial

p2q + pq2

two terms

Binomial

2p + 2q

two terms

Binomial

3.  Add the following.
(i) ab – bc, bc – ca, ca – ab
 (ii) a – b + ab, b – c + bc, c – a + ac
 (iii) 2p2q2 – 3pq + 4, 5 + 7pq – 3p2q2
 (iv) l2 + m2, m2 + n2, n2 + l2, 2lm + 2mn + 2nl

Solution:

i) (ab – bc) + (bc – ca) + (ca-ab)
= ab – bc + bc – ca + ca – ab
= ab – ab – bc + bc – ca + ca

= 0

ii) (a – b + ab) + (b – c + bc) + (c – a + ac)
= a – b + ab + b – c + bc + c – a + ac

= a – a +b – b +c – c + ab + bc + ca

=0 + 0 + 0 + ab + bc + ca

= ab + bc + ca

iii) 2p2q2 – 3pq + 4, 5 + 7pq – 3p2q2
= (2p2q2 – 3pq + 4) + (5 + 7pq – 3p2q2)
= 2p2q2 – 3p2q2 – 3pq + 7pq + 4 + 5
= – p2q2 + 4pq + 9

iv)  (l2 + m2) + (m2 + n2) + (n2 + l2) + (2lm + 2mn + 2nl)
= l2 + l2 + m2 + m2 + n2 + n2 + 2lm + 2mn + 2nl
= 2l2 + 2m2 + 2n2 + 2lm + 2mn + 2nl

4. (a) Subtract 4a – 7ab + 3b + 12 from 12a – 9ab + 5b – 3

(b) Subtract 3xy + 5yz – 7zx from 5xy – 2yz – 2zx + 10xyz

 (c) Subtract 4p2q – 3pq + 5pq2 – 8p + 7q – 10 from 18 – 3p – 11q + 5pq – 2pq2 + 5p2q

Solution:

(a) (12a – 9ab + 5b – 3) – (4a – 7ab + 3b + 12)

= 12a – 9ab + 5b – 3 – 4a + 7ab – 3b – 12

= 12a – 4a -9ab + 7ab +5b – 3b -3 -12

= 8a – 2ab + 2b – 15

b) (5xy – 2yz – 2zx + 10xyz) – (3xy + 5yz – 7zx)

= 5xy – 2yz – 2zx + 10xyz – 3xy – 5yz + 7zx

=5xy – 3xy – 2yz – 5yz – 2zx + 7zx + 10xyz

= 2xy – 7yz + 5zx + 10xyz

c) (18 – 3p – 11q + 5pq – 2pq2 + 5p2q) – (4p2q – 3pq + 5pq2 – 8p + 7q – 10)

= 18 – 3p – 11q + 5pq – 2pq2 + 5p2q – 4p2q + 3pq – 5pq2 + 8p – 7q + 10

=18+10 -3p+8p -11q – 7q + 5 pq+ 3pq- 2pq^2 – 5pq^2 + 5 p^2 q – 4p^2 q

= 28 + 5p – 18q + 8pq – 7pq2 + p2q

Access other exercise solutions of class 8 Maths Chapter 9 Algebraic Expressions and Identities

Exercise 9.2 Solutions : 5 Questions (Short answers)

Exercise 9.3 Solutions : 5 Questions (Short answers)

Exercise 9.4 Solutions : 3 Questions (Short answers)

Exercise 9.5 Solutions : 8 Questions (Short answers)

NCERT Solutions for class 8 Maths Chapter 9 Algebraic Expressions and Identities Exercise 9.1

This exercise of class 8 Maths Chapter 9 Algebraic Expressions and Identities is based on the polynomial terms, factors and coefficients, addition and subtraction of algebraic expressions. Addition and Subtraction operations are mainly performed on monomials, binomials and on polynomials. After practicing these questions students will get confident about the concept and able to solve problems at their own.

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