Question

2^x-2^(x-1)=4 find x

Answer 1

let 2^x=t
so,
t-t/2-4=0
t/2-4=0
t=8
now put t=2^x
2^x=8
2^x=2^3
so, x=3

Answer 2

2^x-2^(x-1)=4
2^x-2^x/2=4
take 2^x common
2^x(1-1/2)=4
2^x*1/2=4
2^x=4*2
2^x=8
2^x=2^3
therefore
x=3