Question 53
For a real number $r$, the quadratics $x^{2}+(r-1)x+6$ and $x^{2}+(2r+1)x+22$ have a common real root. The sum of the possible values of $r$ can be expressed as $\frac{a}{b}$, where $a, b$ are relatively prime positive integers. Compute $100a+b$.