$$3 { x }^{ 2 } -6x+k=0$$
$k=-3x\left(x-2\right)$
$x=\frac{\sqrt{9-3k}}{3}+1$
$x=-\frac{\sqrt{9-3k}}{3}+1$
$x=\frac{\sqrt{9-3k}}{3}+1$
$x=-\frac{\sqrt{9-3k}}{3}+1\text{, }k\leq 3$
