Question

$X-Y \ XY- x^{2}$   -$3-Y \ XY- Y^{2}$

Answer 1

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

Answer 2

(x-y)/(xy-x²) -(3-y)/(xy-y²)=(x-y)/x(y-x)+(3-y)y(y-x)=(xy-y²+3x-xy)/xy(y-x)=
=(3x-y²)/xy(y-x)