Ответ:

[tex] \frac{y \times (y - 1)}{y - 2} \times \frac{2y \times (y - 2)}{(y - 1) \times (y + 1)} \times \frac{y { } ^{2} + y}{2y {}^{3} } [/tex]

[tex]y \times \frac{1}{y + 1} \times \frac{y \times (y + 1)}{y {}^{2} } [/tex]

[tex] \frac{y}{y} [/tex]

[tex]1[/tex]