#### Answer

$\frac{5n-72}{n(n-9)}$

#### Work Step by Step

By inspection, we see that the LCM of the denominators is $n(n-9)$. Therefore, we create a common denominator using this LCM and obtain:
$\frac{8}{n}-\frac{3}{n-9}$
=$\frac{8(n-9)-3(n)}{n(n-9)}$
=$\frac{8n-3n-72}{n(n-9)}$
=$\frac{5n-72}{n(n-9)}$