$$\begin{cases}y+2=C\\ x^{2}y=18\end{cases}$$
$x=3\sqrt{2}\left(C-2\right)^{-\frac{1}{2}}\text{, }y=C-2$
$x=-3\sqrt{2}\left(C-2\right)^{-\frac{1}{2}}\text{, }y=C-2\text{, }C\neq 2$
$x=-3\sqrt{\frac{2}{C-2}}\text{, }y=C-2$
$x=3\sqrt{\frac{2}{C-2}}\text{, }y=C-2\text{, }C>2$
