$$\frac{ 2 }{ { x }^{ 2 } -1 } - \frac{ 1 }{ y-1 } = \frac{ 2 }{ 1 }$$
$y=-\frac{x^{2}-3}{2\left(2-x^{2}\right)}$
$x\neq -1\text{ and }x\neq 1\text{ and }x\neq -\sqrt{2}\text{ and }x\neq \sqrt{2}$
$y=-\frac{x^{2}-3}{2\left(2-x^{2}\right)}$
$|x|\neq \sqrt{2}\text{ and }|x|\neq 1$
$x=-i\left(1-2y\right)^{-\frac{1}{2}}\sqrt{4y-3}$
$x=i\left(1-2y\right)^{-\frac{1}{2}}\sqrt{4y-3}\text{, }y\neq 1\text{ and }y\neq \frac{1}{2}$
$x=\sqrt{-\frac{4y-3}{1-2y}}$
$x=-\sqrt{-\frac{4y-3}{1-2y}}\text{, }y<\frac{1}{2}\text{ or }\left(y\neq 1\text{ and }y\geq \frac{3}{4}\right)$