Question

Given that 2^x = 7, find the value of 4^x-1.

Answer 1

49/4

Explanation:

4^x-1 = (2^x)^2/4 = 7^2/4 = 49/4

Answer 2

`4=2^2\\\\4^x=(2^2)^x=(2^x)^2=7^2=49\\\\4^x-1=49-1=48`

`If\ is\ 4^(x-1),\ then\\\\4^(x-1)=(4^x)/(4)=(49)/(4)=12(1)/(4)`

`Used:\\(a^n)/(a^m)=a^(n-m)`