please help

Question

find the inverse function f-1(x) if

f(x)=10^(3x)

f(x)=log2(4x)

Thanks a lot

Answer 1

x = 10^(3y)
log x = 3 y log 10 = 3 y
y = (1/3) log x

x = log2(4y)
2^x = 4 y
y = (1/4)2^x