Дам 30 баллов !!!! решите плиз номер 559(2))

Решите задачу:

$(x-\frac{x+y}{x-y}+y):(1- \frac{2y+1}{x^2-y^2})= \\\\ =\frac{x(x-y)-(x+y)+y(x-y)}{x-y} : \frac{x^2-y^2-(2y+1)}{x^2-y^2}= \\\\ =\frac{x^2-xy-x-y+xy-y^2}{x-y} \cdot \frac{x^2-y^2}{x^2-y^2-2y-1}= \\\\ =\frac{x^2-y^2-(x+y)}{x-y} \cdot \frac{(x-y)(x+y)}{x^2-(y^2+2y+1)}= \\\\ =((x-y)(x+y)-(x+y)) \cdot \frac{x+y}{x^2-(y+1)^2}= \\\\ =(x-y-1)(x+y) \cdot \frac{x+y}{(x-y-1)(x+y+1)}= \\\\ =\frac{(x+y)^2}{x+y+1}$