Question

помогите пожалуйста!!!!!! ​

Answer 1

$dfrac{r^2-36}{r+3}cdot dfrac{1}{r^2+6r}-dfrac{r+6}{r^2-3r}=dfrac{(r-6)(r+6)}{(r+3)cdot rcdot (r+6)}-dfrac{r+6}{r(r-3)}=\\\=dfrac{(r-6)(r-3)-(r+6)(r+3)}{rcdot (r+3)cdot (r+3)}=dfrac{r^2-9r+18-(r^2+9r+18)}{rcdot (r+3)(r-3)}=\\\=dfrac{-18r}{rcdot (r+3)(r-3)}=-dfrac{18}{r^2-9}=dfrac{18}{9-r^2}$