Answer
$\frac{2}{5}$
Work Step by Step
First, we multiply the numerators by each other and the denominators by each other:
$-\frac{7x}{12y}\times-\frac{24y}{35x}=\frac{7x\times24y}{12y\times35x}=\frac{168xy}{420xy}$
Next, we simplify the resultant expression to obtain the answer:
$\frac{168xy}{420xy}=\frac{168}{420}=\frac{84}{210}=\frac{42}{105}=\frac{2}{5}$
