## Elementary Algebra

$\frac{2}{5}$
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: $\frac{168xy}{420xy}=\frac{168}{420}=\frac{84}{210}=\frac{42}{105}=\frac{2}{5}$