Question

Помогите
Упростите выражение:

Answer 1

$\frac{3-y}{y^{2}-xy }+\frac{x-3}{xy-x^{2} }=\frac{3-y}{y(y-x)}+\frac{x-3}{x(y-x)}=\frac{3x-xy+xy-3y}{xy(y-x)}=\frac{3x-3y}{xy(y-x)}=\frac{3(x-y)}{xy(y-x)}=-\frac{3}{xy}$