Algebra

Combining all like terms and moving all terms to one side, we get 

$x^{2}+12x-4=0$

The two roots of this are

$x=2\sqrt{10}-6\\ x=-2\sqrt{10}-6$

Squaring them we get 

$4\left(\sqrt{10}\right)^{2}-12\sqrt{10}-6\left(2\sqrt{10}-6\right)+\left(-2\sqrt{10}-6\right)^{2}$

$4\cdot 10-12\sqrt{10}-6\left(2\sqrt{10}-6\right)+\left(-2\sqrt{10}-6\right)^{2}$

This simplifies to 152, which is our answer.

Thanks! :)