# NCERT Solutions for Class 8 Maths Chapter 9 (Ex 9.5) Algebraic Expressions and Identities

## NCERT Solutions for Class 8 Chapter 9 Algebraic Expressions and Identities -Free PDF Download

Free PDF download of NCERT Solutions Maths Class 8 Solutions Chapter 9 – Algebraic Expressions and Identities solved by Expert Maths Teachers on CoolGyan.Org. All Chapter 9 – Algebraic Expressions and Identities Questions with Solutions for NCERT to help you to revise complete Syllabus and Score More marks.
Maths Revision Notes for Class 8

 Chapter Name Algebraic Expressions and Identities Chapter Chapter 9 Exercise Exercise 9.5 Class Class 8 Subject Maths NCERT Solutions Board CBSE TEXTBOOK CBSE NCERT Category NCERT Solutions

# NCERT SOLVED

1. Use a suitable identity to get each of the following products:

(i)

(ii)

(iii)

(iv)

(v)

(vi)

(vii)

(viii)

(ix)

(x)

Ans. (i)

[Using identity ]

(ii)

[Using identity ]

(iii)

[Using identity ]

(iv)

[Using identity ]

(v)

[Using identity ]

(vi)

[Using identity ]

(vii)

[Using identity ]

(viii)

[Using identity ]

(ix)

[Using identity ]

(x)

[Using identity ]

2. Use the identity  to find the following products:

(i)

(ii)

(iii)

(iv)

(v)

(vi)

(vii)

Ans. (i)

[Using identity ]

(ii)

[Using identity ]

(iii)

[Using identity ]

(iv)

=(4x)2+{5+(-1)}(4x)+(5)(-1)

[Using identity ]

(v)

[Using identity ]

(vi)

[Using identity ]

(vii)

[Using identity ]

3. Find the following squares by using identities:

(i)

(ii)

(iii)

(iv)

(v)

(vi)

Ans. (i)

[Using identity ]

(ii)

[Using identity ]

(iii)

[Using identity ]

(iv)

[Using identity ]

(v)

[Using identity ]

(vi)

[Using identity ]

4. Simplify:

(i)

(ii)

(iii)

(iv)

(v)

(vi)

(vii)

Ans. (i)

[Using identity ]

(ii)

={(2x+5)+(2x-5)}{(2x+5)-(2x-5)}

[Using identity (a2-b2)=(a+b)(a-b)]

={4x}{2x+5-2x+5}

=(4x)(10)

=40x

(iii)

[Using identities and ]

=

=

(iv)

[Using identity ]

(v)

[Using identity ]

=

(vi)

[Using identity ]

(vii)

[Using identity ]

5. Show that:

(i)

(ii)

(iii)

(iv)

(v)

Ans. (i) L.H.S. =

[Using identity ]

[]

= R.H.S.

(ii) L.H.S. =

[Using identity ]

[]

(iii) L.H.S. =

[Using identity ]

= R.H.S.

(iv) L.H.S. =

[Using identities and ]

= R.H.S.

(v)L.H.S.=

[Using identity ]

= 0

= R.H.S.

6. Using identities, evaluate:

(i)

(ii)

(iii)

(iv)

(v)

(vi)

(vii)

(viii)

(ix) 10.5 ×× 9.5

Ans. (i)

[Using identity ]

= 4900 + 140 + 1 = 5041

(ii)

[Using identity ]

= 10000 – 200 + 1 = 9801

(iii)

[Using identity ]

= 10000 + 400 + 4 = 10404

(iv)

[Using identity ]

= 1000000 – 4000 + 4 = 996004

(v)

[Using identity ]

= 25 + 2.0 + 0.04 = 27.04

(vi)

[Using identity ]

= 90000 – 9 = 89991

(vii)

[Using identity ]

= 6400 – 4 = 6396

(viii)

[Using identity ]

= 64 + 14.4 + 0.81 = 79.21

(ix) 10.5 x 9.5 =

[Using identity ]

= 100 – 0.25 = 99.75

7. Using  find

(i)

(ii)

(iii)

(iv)

Ans. (i)

[Using identity ]

= 200

(ii)

[Using identity ]

= 0.08

(iii)

[Using identity ]

= 1800

(iv)

[Using identity ]

= 84.0 = 84

8. Using , find

(i)

(ii)

(iii)

(iv)

Ans. (i)

[Using identity ]

= 10000 + 700 + 12 = 10712

(ii)

[Using identity ]

= 25 + 1.5 + 0.02 = 26.52

(iii)

[Using identity ]

= 10000 + 100 – 6 = 10094

(iv)

[Using identity ]

= 100 – 5 + 0.06 = 95.06