Answer
$\frac{13x-72}{x(x-8)}$
Work Step by Step
By inspection, we see that the LCM of the denominators is $x(x-8)$. Therefore, we create a common denominator using this LCM and obtain:
$\frac{4}{x-8}+\frac{9}{x}$
=$\frac{x(4)+9(x-8)}{x(x-8)}$
=$\frac{4x+9x-72}{x(x-8)}$
=$\frac{13x-72}{x(x-8)}$
