Answer
$= \frac{2}{7}$
Work Step by Step
We first multiply the numerators and the denominators of the fractions by each other. Then, we simplify the fractions to obtain:
$(\frac{-3x}{12y})(\frac{8y}{-7x})$
$= \frac{-3x(8y)}{12y(-7x)}$
$= \frac{-24xy}{-84xy}$
$= \frac{2}{7}$
