Решите пожалуйста срочно надо!!!!

7)
$(\frac{x-y}{x^2+yx}- \frac{x}{y^2+xy}):( \frac{1}{x+y} + \frac{y^2}{x^3-xy^2})+ \frac{x}{y} =1 \\ \\ 1) \frac{x-y}{x^2+yx}- \frac{x}{y^2+xy}= \frac{xy-y^2-x^2}{xy(x+y)}=- \frac{x^2-xy+y^2}{xy(x+y)} \\ \\ 2)\frac{1}{x+y} + \frac{y^2}{x^3-xy^2}= \frac{x^2-xy+y^2}{x(x-y)(x+y)} \\ \\ 3) - \frac{x^2-xy+y^2}{xy(x+y)} :\frac{x^2-xy+y^2}{x(x-y)(x+y)}=- \frac{x^2-xy+y^2}{xy(x+y)} * \frac{x(x-y)(x+y)}{x^2-xy+y^2} =\\ \\ =- \frac{x-y}{y}= \frac{y-x}{y} \\ \\ 4)\frac{y-x}{y}+ \frac{x}{y} = \frac{y-x+x}{y}=1$

9)

$(\frac{x+y}{x-y}+ \frac{x-y}{x+y}):(\frac{x+y}{x-y}-\frac{x-y}{x+y})* \frac{x^2y^2}{(x-y)^2+(x+y)^2}= \frac{xy}{4} \\ \\ 1)\frac{x+y}{x-y}+ \frac{x-y}{x+y}= \frac{x^2+xy+xy+y^2+x^2-xy-xy+y^2}{(x-y)(x+y)}= \frac{2(x^2+y^2)}{(x-y)(x+y)} \\ \\ 2)\frac{x+y}{x-y}-\frac{x-y}{x+y}= \frac{x^2+xy+xy+y^2-x^2+xy+xy-y^2}{(x-y)(x+y)} = \frac{4xy}{(x-y)(x+y)} \\ \\ 3)\frac{2(x^2+y^2)}{(x-y)(x+y)} :\frac{4xy}{(x-y)(x+y)}=\frac{2(x^2+y^2)}{(x-y)(x+y)}* \frac{(x-y)(x+y)}{4xy}= \frac{x^2+y^2}{2xy}$

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