#### Answer

$\frac{x}{x-y}$

#### Work Step by Step

We factor the expression in the denominator in order to cancel out common factors in the numerator and the denominator:
$\frac{x^{3}}{x^{3}-x^{2}y}$
=$\frac{x^{3}}{x^{2}(x-y)}$
=$\frac{x^{3-2}}{(x-y)}$
=$\frac{x}{x-y}$