Answer
$-18$
Work Step by Step
Recall the acronym PEDMAS, which tells us the order of operations:
P: Parenthesis and other grouping symbols
E: Exponents
D/M: Division and Multiplication (from left to right)
A/S: Addition and Subtraction (from left to right)
Use the rule above to obtain:
$=-3[4-(-2)]$ (Recall, $a-(-b)=a+b)$.
$\\=-3[4+2]
\\=-3(6)
\\=-18$
