Answer
$\frac{6}{13}$
Work Step by Step
First, we multiply the numerators by each other and the denominators by each other:
$-\frac{10a}{15b}\times-\frac{45b}{65a}=\frac{10a\times45b}{15b\times65a}=\frac{450ab}{975ab}$
Next, we simplify the resulting expression to obtain the answer:
$\frac{450ab}{975ab}=\frac{450}{975}=\frac{150}{325}=\frac{30}{65}=\frac{6}{13}$