Evaluate the following expressions for $x = 2$, $y = -4$, and $z = -5$ without using a calculator. Simplify your answers as much as possible, and enter your answers as fractions. help (fractions)

$\displaystyle \left( \frac{x^3 y}{2z} \right)^2$	=
$\displaystyle \left( \frac{x+y}{x-z} \right)^x$	=