$$12ky^{2}+6ky-20k$$
$2k\left(6y^{2}+3y-10\right)$
$12k\left(y-\left(-\frac{\sqrt{249}}{12}-\frac{1}{4}\right)\right)\left(y-\left(\frac{\sqrt{249}}{12}-\frac{1}{4}\right)\right)$
