Answer
$$r=\sqrt{\frac{7}{2}}-1,\:r=-\sqrt{\frac{7}{2}}-1$$
Work Step by Step
Completing the square to solve the equation, we find:
$$ 2\left(r^2+2r-\frac{5}{2}+1^2-1^2\right) \\ 2\left(\left(r+1\right)^2-\frac{5}{2}-1^2\right) \\ 2\left(r+1\right)^2-7 \\ \left(r+1\right)^2=\frac{7}{2} \\ r=\sqrt{\frac{7}{2}}-1,\:r=-\sqrt{\frac{7}{2}}-1$$
