$$Kx(x-2)+6=0$$
$K=-\frac{6}{x\left(x-2\right)}$
$x\neq 2\text{ and }x\neq 0$
$x=\frac{\sqrt{K\left(K-6\right)}+K}{K}$
$x=\frac{-\sqrt{K\left(K-6\right)}+K}{K}\text{, }K\neq 0$
$x=\frac{\sqrt{K\left(K-6\right)}+K}{K}$
$x=\frac{-\sqrt{K\left(K-6\right)}+K}{K}\text{, }K<0\text{ or }K\geq 6$