$$\frac{x^{2}y}{x-y}-\frac{xy^{2}}{x+y}$$
$\frac{xy\left(x^{2}+y^{2}\right)}{x^{2}-y^{2}}$
$\frac{xy\left(x^{2}+y^{2}\right)}{\left(x-y\right)\left(x+y\right)}$
