Question

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

Answer 1

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