Answer
$\frac{3}{4}$
Work Step by Step
$-\frac{9}{7}(-\frac{21}{36})=-\frac{9}{7}\times-\frac{21}{36}=\frac{-9\times-21}{7\times36}=\frac{189}{252}=\frac{189\div63}{252\div63}=\frac{3}{4}$
The numbers being multiplied together have the same sign, so their resulting product is positive.
