Let x \mathbin{\spadesuit} y = \frac{x^2}{y} for all x and y such that y\neq 0. Find all values of $a$ such that $a \mathbin{\spadesuit} (a + 1) = 9$. Write your answer as a list separated by commas.

Let's call this "spadesuit" a function called g, so, A g B=a^2/y

which would conclude that a can be \(\frac{9 - 3\sqrt{13}}{2}\), and \(\frac{9 + 3\sqrt{13}}{2}\).