Ncert Solutions For Class 8 Maths Ex 1.1

Ncert Solutions For Class 8 Maths Chapter 1 Ex 1.1

  1. Using appropriate properties find the value of 23×35+5235×16

Sol.   23×35+5235×1623×3535×16+52

=35(23+16)+52

=35(4+16)+52

=35(56)+52

=1530+52

=12+52

=42

=2

 therefore23×35+5235×16 =2

 

  1. Using appropriate properties find the value of 25×3716×32+114×25

Sol. 25×3716×32+114×25

= 25×3712×12+17×15

=63514+135

=53514

=1714

=1128

=25×3716×32+114×25

=1128

 

  1. Solving the additive inverse of 28

Sol.  Additive inverse of 28is28

 

  1. Solving the additive inverse of 59

Sol.  Additive inverse of 59is59

 

  1. Solving the additive inverse of 65

Sol. 6565

Additive inverse of 65is65

Additive inverse of 6565

 

  1. Solving the additive inverse of 29

Sol.  Additive inverse of 29is29

 

  1. Verify that –(-x )=x for x=1115

Sol. x=1115

x=1115 (x)=(1115)

=1115=x

 therefore(x)=x

 

  1. Verify that –(-x )=x for x=1317

Sol. x=1317

x=(1317)=1317 (x)=(1317)

=1317=x

 therefore(x)=x

 

  1. Solve that multiplicative inverse of -13

Sol. Given multiplicative inverse -13 is113

 

  1. Solve that multiplicative inverse of 1319

Sol. Given multiplicative inverse 1319is1913

 

  1. Solve that multiplicative inverse of 58×37

Sol. Given multiplicative inverse 58×37is 85×73 or 85×73

 

  1. What is the multiplicative inverse of -1.

Sol.  The multiplicative inverse of -1 is -1.

 

  1. Name the property under multiplicative used in each of the following.

 (i) 45×1=1×45=45

(ii) 1317×27=27×1317

(iii) 1929×2919=1

Sol. (i) ROLE OF 1

(ii) COMMUTATIVITY

(iii) MULTIPLICATIVE  INVERSE

 

  1. Multiply 613 by the reciprocal of 76

Sol. Reciprocal of 76 is 67

 therefore613×67

=3691

 

  1. what property allows you to compute 13×(6×43)(13×6)×45

Sol.  Associativity

 

  1. Is 89 the multiplicative inverse of 118 ? why or why not.

Sol.

118=98

=89×98

=11

 therefore89 is  not the multiplicative inverse of 118

 

  1. Is 0.3 the multiplicative inverse of 313 ? why or why not.

Sol.        313=103=3.3

                          3.3×0.3=0.991

 therefore0.3isnotthemultiplicativeinverseof313