$$y ( \frac { 1 } { x + 1 } + \frac { 1 } { x - 1 } ) ( \frac { 2 } { 2 x + 1 } + \frac { 2 } { 2 x - 1 } )$$
$\frac{16yx^{2}}{\left(4x^{2}-1\right)\left(x^{2}-1\right)}$
$|x|\neq 1\text{ and }|x|\neq \frac{1}{2}$
$\frac{16yx^{2}}{\left(4x^{2}-1\right)\left(x^{2}-1\right)}$
$|x|\neq 1\text{ and }|x|\neq \frac{1}{2}$