inverse of y=12^x

y = 12^x       take the log of both sides

log y  = log 12^x    and we can write

log y =  x log 12     divide both sides by log (12)

log y / log (12)  = x     exchange x and y

log x / log 12  =  y     for y.......write f^-1 (x)

So

f^-1(x)  = log x / log 12

Here' sthe graph of both the original function and the inverse : https://www.desmos.com/calculator/beo7z7kzbj

for what value of x does 64^3x = 512^ 2x=12