-2y
Пошаговое объяснение:
((x-y)/(√x -√y) -(x-y)/(√x +√y))/((√x -√y)/(x-y) +(√x +√y)/(x-y)) ·(2√(xy))/(y-x)=
((x-y)(√x +√y -√x +√y))/(x-y) ·(x-y)/(√x -√y +√x +√y) ·(-2√(xy))/(x-y)=-(2√(xy) ·2√y)/(2√x)=-2√y ·√y=-2y
