Помогите пожалуйста сделать номер 573

[latex]1) ( \frac{a}{a+1}+1):(1- \frac{3a^2}{1-a^2})= ( \frac{a+a+1}{a+1} ):( \frac{1-a^2-3a^2}{(1-a)(1+a)} ) \\ = \frac{2a+1}{a+1}: \frac{1-4a^2}{(1-a)(1+a)}= \frac{2a+1}{a+1}* \frac{(1-a)(1+a)}{(1-2a)(1+2a)}= \frac{1-a}{1-2a}; \\ 2) ( \frac{2m+1}{2m-1}- \frac{2m-1}{2m+1}): \frac{4m}{10m-5}=( \frac{4m^2+4m+1-4m^2+4m-1}{(2m-1)(2m+1)})* \frac{5(2m-1)}{4m}= \\ = \frac{8m}{(2m-1)(2m+1)}* \frac{5(2m-1)}{4m}= \frac{10}{2m+1}; \\ [/latex] [latex]3) ( \frac{a}{x-a}+ \frac{a}{x+a})* \frac{x^2+2ax+a^2}{2a^2}= \frac{ax+a^2+ax-a^2}{(x-a)(x+a)}* \frac{(x+a)^2}{2a^2}= \\ =\frac{2ax}{(x-a)(x+a)}* \frac{(x+a)^2}{2a^2}= \frac{x(x+a)}{(x-a)*a}= \frac{x^2+ax}{ax-a^2}; \\ 4) ( \frac{x^2}{y^2}+ \frac{y}{x}):( \frac{x}{y^2}- \frac{1}{y} + \frac{1}{x})= \frac{x^3+y^3}{xy^2}: \frac{x^2-xy+y^2}{xy^2}= \frac{x^3+y^3}{xy^2}* \frac{xy^2}{x^2-xy+y^2}= \\ \frac{(x+y)(x^2-xy+y^2)}{x^2-xy+y^2}=x+y. [/latex]