Question

$\frac{a-b}{b}*(\frac{b}{b-a}+\frac{b}{a})$

Answer 1

Решение во вложении.

Answer 2

$\frac{a-b}{b}*(\frac{b}{b-a}+\frac{b}{a})=(a-b)*(-\frac{1}{a-b}+\frac{1}{a})=-1+\frac{a-b}{a}=\frac{-a+a-b}{a}=-\frac{b}{a}$