Question

Найдите сумму или разность:

Answer 1

$frac{9}{b(b+3)}-frac{3}{b}=frac{9}{b(b+3)}-frac{3(b+3)}{b(b+3)}=frac{9-3b-9}{b(b+3)}=frac{-3b}{b(b+3)}=frac{-3}{b+3}$

$8b+frac{5-9b^2}{b}=frac{8b^2}{b}+frac{5-9b^2}{b}=frac{8b^2+5-9b^2}{b}=frac{5-b^2}{b}$