Question

If x= eighth root of y and y= z^16 how is x proportionate to z ?

Answer 1

$x= \sqrt[8]{y} \\ y = z^{16}$

Plug "y" into the first equation.

$x = \sqrt[8]{z^{16}} = (z^{16})^{1/8} = z^{16/8} = z^2$