Answer
$(a)$ $-6$
$(b)$ $-1$
Work Step by Step
$-2x^{3}+3x^{2}-6$
$(a)$ $x=0$
Replace $x$ with $0$ and evaluate the indicated operations:
$-2(0)^{3}+3(0)^{2}-6=-6$
Replace $x$ with $-1$ and evaluate the indicated operations:
$-2(-1)^{3}+3(-1)^{2}-6=2+3-6=-1$