Find all values of r such that

Just a side note, make sure to put $ around your LaTeX so it renders properly, and put \sqrt{} instead of sqrt().

 

Multiplying both sides by $\sqrt{r}$ gives $r-3=-2*\sqrt{r}*\sqrt{r}$. Simplifying the right hand side gives $r-3=-2r$, and subtracting r from both sides gives $-3=-3r$. Dividing by -3 gives $\boxed{r=1}$