Question

помогите пожалуйста ​

Answer 1

$frac{x-y}{x+y} -frac{x+y}{x-y} =frac{(x-y)^2-(x+y)^2}{(x+y)(x-y)} =frac{x^2-2xy+y^2-(x^2+2xy+y^2)}{(x+y)(x-y)} =frac{x^2-2xy+y^2-x^2-2xy-y^2}{(x+y)(x-y)} =frac{-4xy}{x^2-y^2} \Otvet: D$