$\left\{\begin{matrix}\\x\in (-\infty,-\sqrt{y^{2}-6y+18}-2)\cup (\sqrt{y^{2}-6y+18}-2,\infty)\text{, }&\text{unconditionally}\\x\in (-\infty,-5]\cup [1,\infty)\text{, }&y<3\\x\in (-\infty,-5)\cup (1,\infty)\text{, }&y\leq 3\end{matrix}\right.$

$y<\sqrt{\left(x-1\right)\left(x+5\right)}+3$
$x\leq -5\text{ or }x\geq 1$