Sagot :
[tex] \frac{2}{r} = \frac{1}{r} -\frac{1}{r}+3\ \ \ and\ \ \ r \neq 0\\\\ \frac{2}{r} =3\ /\cdot r\\\\2=3r\ /:3\\\\ \frac{2}{3} =r[/tex]
[tex]\frac{2}{r}=\frac{1}{r}-\frac{1}{r+3};\ D:r\neq0\ \wedge\ r\neq-3\\\\\frac{2}{r}-\frac{1}{r}=\frac{-1}{r+3}\\\\\frac{1}{r}=\frac{-1}{r+3}\\\\cross\ multiply\\\\r+3=-r\\\\r+r=-3\\\\2r=-3\\\\\boxed{r=-1.5}[/tex]