Question

$( frac{a+3}{a-3} + frac{a-3}{a+3}) : frac{3a^2+27}{9-a^{2} }$Упростите выражение (a+3/a−3+a−3/a+3):3a^2+27/9−a^2.

Answer 1

$(frac{a+3}{a-3}+frac{a-3}{a+3}):frac{3a^2+27}{9-a^{2}}=$

$(frac{(a+3)^2}{(a-3)(a+3)}+frac{(a-3)^2}{(a+3)(a-3)})*frac{9-a^{2}}{3a^2+27}=$

$frac{a^2+6a+9+a^2-6a+9}{a^2-9}*frac{-(a^{2}-9)}{3a^2+27}=$

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

Answer 2

https://znanija.com/task/29884517