NCERT Solutions For Class 8 Math Chapter -12 Exponents and Power Exercise -12.1

NCERT Solution For Class 8 Math Chapter – 12 Exponents and Power Exercise – 12.1

Q1. Evaluate:

  • 3-2
  • (-4)-2
  • (1/2)-5

Solution:-

 

  • 3-2

= 1/9

 

  • (-4)-2

=  1/16

 

  • (1/2)-5

= 32

 

Q2. Simplify and express the result in power notation with positive exponent:

  • (-4)4 / (-4)8
  • (1/23)2
  • -(3)4 x (5/3)4
  • (3-7 / 3-10) x 3-5
  • 2-3 x (-7)-3

Solution:-

 

  • (-4)5 / (-4)8

= 1/(-4)3

 

  • (1/23)2

= 1/23 x 2

= 1/26

 

  • (-3)4 x (5/3)4

= 30 x 54 = 54

 

  • (3-7 / 3-10) x 3-5

= 1/32

 

  • 2-3 x (-7)-3

= 1(-14)3

 

Q3. Find the value of:

  • (30 + 4-1) x 22
  • (2-1 x 4-1) / 2-2
  • (1/2)-2 + (1/3)-2 + (1/4)-2
  • (3-1 + 4-1 + 5-1 )0

(V) {(-2/3)-2}2

 

Solution:-

 

(i)

= (1 +(1/4) x 22

= (4 + 1)/4) x 22

= (5/4) x 22

= (5/22) x 22

= 5

x 2 ( 2 – 2 )

= 5 x 1

= 5

 

(ii)

= [(1/2) x (1/4)] / (1/4)

= (1/8) x (4)

= 1/2

 

(iii)

= (2-1)-2 + (3-1)-2 +  (4-1)-2

= 4 + 9 + 16

= 29

 

(iv)

= 1

 

(v)

= (-2/3)-4

= (-3/2)4

= 81/16

 

Q4. Evaluate

  • (8-1 x 53)/2-4
  • (5-1 x 2-2 ) x 6-1

 

Solution:-

 

(i)

= 2 x 1 25

= 250

 

(ii)

= (1/10) x 1/6

= 1/60

 

Q5. Find the value of m for which 5m / 5-3 = 55

Solution:-

 

5m / 5-3 = 55

5(m-(-3))  = 55

5m+3 = 55

M + 3 = 5

M = 5 – 3

M = 2

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Q6. Evaluate

(i)

 

{ (1/3)-1 – (1/4)-1}-1

 

(ii)

 

(5/8)-7 x (8/5)-4

 

Solution:-

 

(i)

= { (3/1)1 – (4/1)1}

= 3 – 4

= -1

 

(ii)

 

= 5-7/8-7 x 8-4/5-4

= 5-7-(-4) x 8-4-(-7)

= 5/2/125

 

Q7. Simplify.

  • 25 x t-4/ 5-3 x 10 x t-3 ( t 0)
  • 3-5 x 10-5 x 125 / 5-7 x 6-5

 

Solution:-

 

(i)

= 52 x t-4/ 5-3  x 5 x 2 x t-8

625/2 t4

 

(ii)

= 3-5 x ( 2 x 5)-5 x 53 / 5-7 x (2 x 3)-5

= 1 x 3125 x 1

= 3125

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NCERT Solution For Class 8 Math Chapter – 12 Exponents and Power Exercise – 12.1 Q1. Evaluate: 3-2 (-4)-2 (1/2)-5 Solution:-…