Question

ПОМОГИТЕ РЕШИТЬ!!!!!

Answer 1

$cfrac{5ac^2}{a^2-9c^2} cdot cfrac{a-3c}{ac}= cfrac{5c}{(a-3c)(a+3c)} cdot cfrac{a-3c}{1}= cfrac{5c}{a+3c}$

при а=22, с=1

$cfrac{5c}{a+3c}=cfrac{5 cdot 1}{22+3 cdot1}=cfrac{5 }{22+3}=cfrac{5 }{25}=cfrac{1}{5}$