Answer
$\frac{-18}{-15+12}$=6
Work Step by Step
"The quotient" means this expression can be written as a fraction. "Of -18 and the sum of -15 and 12 means that -18 goes on the top and (-15+12) goes on the bottom.
$\frac{-18}{-15+12}$=$\frac{-18}{-3}$=6