Question

Given that 2^x=7 then what is 4^x-1

Answer 1

It depend what you mean

First    4∧x -1 = (2∧2)∧x -1 = (2∧x)∧2 -1 = 7∧2 -1 = 49-1 = 48

Second  4∧(x-1)= (2∧2)∧(x-1)=2∧(2x-2)=(2∧x)∧2/4=7∧2/4=49/4

Answer 2

4^x=2×2^x=2×7=14
4^x-1=14-1=13