# How much is my partner worth?

Algebra Level 2

$\begin{eqnarray}x^2 + y^2 + xy&=& 18\\ x + y + \sqrt{xy}&=& 6 \\ x + y - \sqrt{xy} &=& \ ? \end{eqnarray}$

Don't be shy to post your solutions if you have a different method!

×