Answer
$-72.$
Work Step by Step
We are given: $x=-3$, $y=4$, $z=6$
We take into account the order of operations:
Parenthesis, Exponents, Multiplication/Division, Addition/Subtraction
Thus, we have:
$$(y^2-2x^2)z^2=(4^2-2(-3)^2)6^2=(16-18)36\\
=-2*36=-72.$$
