Question

СРОЧНО ДАЮ 30 БАЛЛОВ

Answer 1

$1)\frac{a}{(a-b)^{2}}-\frac{b}{a^{2}-b^{2}}=\frac{a}{(a-b)^{2}}-\frac{b}{(a-b)(a+b)}=\frac{a*(a+b)-b*(a-b)}{(a-b)^{2}(a+b) }=\frac{a^{2}+ab-ab+b^{2}}{(a-b)^{2}(a+b)}=\\\\=\frac{a^{2}+b^{2}}{(a-b)^{2}(a+b)}\\\\2)\frac{a^{3}-ab^{2}}{a^{2}+b^{2}}*\frac{a^{2}+b^{2}}{(a-b)^{2}(a+b)}=\frac{a(a^{2}-b^{2})*(a^{2}+b^{2})}{(a^{2}+b^{2})(a^{2}-b^{2})(a-b)}=\frac{a}{a-b}\\\\3)\frac{b}{a-b}-\frac{a}{a-b}=\frac{b-a}{a-b}=-\frac{a-b}{a-b}=-1\\\\Otvet:\boxed{-1}$