Question

13. If 2x – 2x-1 = 4, find the value of xx :
(a) 3
(b) 9
(c) 27
(d) 81​

Answer 1

Answer:

2x−2x−1=4

⇒(21×2x−1)−2x−1=4

or 2x−1(2−1)=4

or 2x−1=22

Since base of both sides of the equation are equal, the powers should also be equal.

⇒x−1=2

 ⇒x=2+1=3

∴xx=33=27