Question

упростите выражение ( 3-у/у^2-xy)+(x-3\xy-x^2)

Answer 1

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