$$\frac{x^{2}+y^{2}}{xy}\cdot\cdot-\frac{x^{2}}{y(x+y)}-\frac{y^{2}}{x(x+y)}$$
$\frac{x^{4}-y^{4}+\left(xy\right)^{2}}{x\left(x+y\right)y^{2}}$
