Помогите пожалуйста с алгеброй задание 9,10 даю 200 балов очень очень срочно заранее...

Решите задачу:

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

$( \frac{1}{a^2} + \frac{1}{b^2} + \frac{2}{a+b} *( \frac{1}{a} + \frac{1}{b} )):( \frac{a+b}{ab} )^2=\\\\=( \frac{1}{a^2} + \frac{1}{b^2} + \frac{2}{a+b}* \frac{b+a}{ab})* \frac{a^2b^2}{(a+b)^2}=\\\\=( \frac{b^2+a^2}{a^2b^2}+ \frac{2}{ab})* \frac{a^2b^2}{(a+b)^2}=\\\\= \frac{a^2+b^2+2ab}{a^2b^2}* \frac{a^2b^2}{a^2+b^2+2ab}= 1$