Question

a
a2 + ab b +1
6.2 -1 a+b
1-5​

Answer 1

Ответ:

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