Find the value of m for which5m ÷ 5-3 = 55

Q4 of 239 Page 25

Find the value of m for which
5^m ÷ 5^-3 = 5⁵

5^m ÷ 5^-3 = 5⁵

(∵ Reciprocal law: If ‘a’ is a real no. and m is a positive integer, then )

where ‘a’ is a non-zero real no. and m, n are positive integers.)

⇒ m = 2 (∵ base is same)

Find the value of:

7^-20 – 7^-21

Find the value of m for which

4^m = 64

Find the value of m for which

8^{m – 3} = 1

Questions · 239

1. Real Number System

1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 5 5 6 6 1 1 1 1 2 2 2 2 3 3 3 3 1 1 1 1 1 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 4 4 4 4 4 4 5 5 6 6 1 2 2 2 2 2 3 3 3 4 4 4 4 5 5 5 5 5 6 6 6 6 6 6 7 7 1 1 1 1 2 2 2 2 3 3 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 9 10 10 10 10 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 3 4 4 4 4 4 4 5 5 5 5 5 6 6 6 6 6 6 6 6 7 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 3 4 4 4 4 4 4 1 1 1 1 1 1 1 2 3