Answer
b) -54
Work Step by Step
Use the order of operations to simplify the expression.
$8(-9)-6(-3)\longrightarrow$ multiply, working left to right
$=-72-6(-3)\longrightarrow$ multiply
$=-72-(-18)\longrightarrow$ change subtraction to addition and reverse the sign of the following term
$=-72+18\longrightarrow$ add
$=-54$