Question

Упростите выражение а^2+9/a^2-9 - a+3/a-3

Answer 1

$\frac{a^{2}+9}{a^{2}-9}- \frac{a+3}{a-3}= \frac{a^{2}+9}{(a-3)(a+3)}- \frac{a+3}{a-3}= \frac{a^{2}+9-(a+3)^{2}}{(a-3)(a+3)}= \frac{a^{2}+9-a^{2}-6a-9}{(a-3)(a+3)}= \frac{-6a}{a^{2}-9}$