Упростите выражение: а) б)

Решите задачу:

$\mathtt{(\frac{x+10}{5x+25}-\frac{1}{x+5})\frac{5}{x-5}-\frac{10}{x^2-25}=\frac{x+5}{5(x+5)}*\frac{5}{x-5}-\frac{10}{x^2-25}=\frac{1}{x-5}-\frac{10}{x^2-25}=}\\\mathtt{\frac{x+5}{x^2-25}-\frac{10}{x^2-25}=\frac{x-5}{x^2-25}=\frac{1}{x+5}=(x+5)^{-1}};$

$\mathtt{\frac{y^2}{y^2-1}+\frac{1}{y^2-1}:(\frac{2}{2y-y^2}-\frac{1}{2-y})=\frac{y^2}{y^2-1}+\frac{1}{y^2-1}:\frac{2-y}{y(2-y)}=\frac{y^2}{y^2-1}+\frac{1}{y^2-1}*y=}\\\mathtt{\frac{y^2+y}{y^2-1}=\frac{y}{y-1}}$