Evaluate
(i) (8⁻¹× 5³)/2⁻⁴    (ii) (5⁻¹× 2⁻¹)×6⁻¹

Solution:

(i) (8⁻¹ × 5³) / 2⁻⁴

According to the rules of exponents,

We know that, a^−m = 1/a^m,a^m÷aⁿ = a^m−n

(8⁻¹× 5³)/2⁻⁴

= (2⁴ × 5³)/8¹ [Since a^−m = 1/a^m]

= (2⁴ × 5³)/2³

= 2^{4 − 3} × 5³ [a^m ÷ aⁿ = a^{m − n}]

= 2 × 125

= 250

(ii) (5⁻¹× 2⁻¹) × 6⁻¹

According to the rules of exponents,

We know that, a^m × b^m = (ab)^m, a^-m = 1/a^m

(5⁻¹ × 2⁻¹) × 6⁻¹

=10⁻¹× 6⁻¹

= (10 × 6)⁻¹ [∵a^m × b^m = (ab)^m]

= (60)⁻¹ = 1/60 [∵ a^-m = 1/a^m]

☛ Check: NCERT Solutions for Class 8 Maths Chapter 12

Video Solution:

Evaluate (i) (8⁻¹ × 5³)/2⁻⁴ (ii) (5⁻¹ × 2⁻¹) × 6⁻¹

Class 8 Maths NCERT Solutions Chapter 12 Exercise 12.1 Question 4

Summary:

The value of the following expressions are: (i) (8⁻¹× 5³)/2^-4 = 250 (ii) (5⁻¹ × 2⁻¹) × 6⁻¹ = 1/60

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