log(x)(1/16) = -4/3

this means...

x^(-4/3)= 1/16

so...the -4/3 root of 1/16...

I need to get it in simplest form.

Continuing,

x^(4/3) = 16
Take the 1/4 root of both sides, and get
x^(1/3)= 2
Cube both sides, and get
x = 8