Question

Упростите выражение: a2 / a2 - 1 - a / a + 1.

Answer 1

$frac{a^2}{(a^2-1)} -frac{a}{(a+1)}=frac{a^2}{(a-1)(a+1)}-frac{a}{(a+1)}=frac{a^2-a(a-1)}{(a-1)(a+1)}=frac{a^2-a^2+1}{a^2-1}=frac{1}{a^2-1}$

Answer 2

$frac{a^{2}}{a^{2}}-frac{1-a}{a+1}=1-frac{1-a}{a+1}=frac{a+1-(1-a)}{a+1}=frac{a+(1-1)+a}{a+1}=frac{a+a}{a+1}=frac{2a}{a+1}$