1.31: Past-paper question 3

Given that $\displaystyle \frac{a+b\sqrt{5}}{6-2\sqrt{5}} = \frac{9+4\sqrt{5}}{c}$ where $\displaystyle a$, $\displaystyle b$ and $\displaystyle c$ are prime numbers, find the value of $\displaystyle a$, the value of $\displaystyle b$ and the value of $\displaystyle c$