Multiply $\frac{x-y}{x^{2}-xy+y^{2}}$ times $\frac{\left(x-y\right)^{2}+xy}{x^{2}-xy}$ by multiplying numerator times numerator and denominator times denominator.
Divide $\frac{\left(x-y\right)\left(\left(x-y\right)^{2}+xy\right)}{\left(x^{2}-xy+y^{2}\right)\left(x^{2}-xy\right)}$ by $\frac{\left(x+2y\right)^{2}-2xy}{x^{3}+xy^{2}}$ by multiplying $\frac{\left(x-y\right)\left(\left(x-y\right)^{2}+xy\right)}{\left(x^{2}-xy+y^{2}\right)\left(x^{2}-xy\right)}$ by the reciprocal of $\frac{\left(x+2y\right)^{2}-2xy}{x^{3}+xy^{2}}$.
Multiply $\frac{x-y}{x^{2}-xy+y^{2}}$ times $\frac{\left(x-y\right)^{2}+xy}{x^{2}-xy}$ by multiplying numerator times numerator and denominator times denominator.
Divide $\frac{\left(x-y\right)\left(\left(x-y\right)^{2}+xy\right)}{\left(x^{2}-xy+y^{2}\right)\left(x^{2}-xy\right)}$ by $\frac{\left(x+2y\right)^{2}-2xy}{x^{3}+xy^{2}}$ by multiplying $\frac{\left(x-y\right)\left(\left(x-y\right)^{2}+xy\right)}{\left(x^{2}-xy+y^{2}\right)\left(x^{2}-xy\right)}$ by the reciprocal of $\frac{\left(x+2y\right)^{2}-2xy}{x^{3}+xy^{2}}$.