The value of (2/5)^-2 is
(a) 4/5
(b) 4/25
(c) 25/4
(d) 5/2

Solution:

The Correct answer is(c)

We have (2/5)^-2

By using laws of indices (a/b)-m = (b/a)m

∴ (2/5)^-2 = (5/2)²

Now using (a/b)^m = a^m/b^m

(5/2)² = 5²/2²

= 25/4

✦ Try This: The value of (4/9)^-3 is (a) 4/9, (b) 729/64, (c) 64/729, (d) 9/4

The Correct answer is(b)

We have by using laws of indices (a/b)^-m = (b/a)^m

∴ (4/9)^-3 = (9/4)³ Now using (a/b)^m = a^m/b^m

(9/4)³ = 9³/4³

= 729/64

☛ Also Check: NCERT Solutions for Class 8 Maths Chapter 12

NCERT Exemplar Class 8 Maths Chapter 8 Problem 6

The value of (2/5)^-2 is (a) 4/5, (b) 4/25, (c) 25/4, (d) 5/2

Summary:

The value of (2/5)^-2 = 25/4

☛ Related Questions:

• The reciprocal of (2/5)-1 is (a) 2/5, (b) 5/2, (c) -5/2, (d) -2/5
• The multiplicative inverse of 10-100 is (a) 10, (b) 100, (c) 10100, (d) 10-100
• The value of (-2)2 × 3 - 1 is (a) -32, (b) -64, (c) 32, (d) 64