Answer
$36$
Work Step by Step
We are given: $x=-1$, $y=2$, $z=-3$
We take into account the order of operations:
Parenthesis, Exponents, Multiplication/Division, Addition/Subtraction
Thus, we have:
$$(3x^2-z^2)^2=(3(-1)^2-(-3)^2)^2\\
=(3-9)^2=(-6)^2=36
.$$
