B) 2/y²-4 - 1/y²+2y.

B) $$\frac{2}{y^2-4} - \frac{1}{y^2+2y} = \frac{2}{(y-2)(y+2)} - \frac{1}{y(y+2)} = \frac{2y - (y-2)}{y(y-2)(y+2)} = \frac{2y-y+2}{y(y-2)(y+2)} = \frac{y+2}{y(y-2)(y+2)} = \frac{1}{y(y-2)}$$

Ответ: $$\frac{1}{y(y-2)}$$