7) $$\frac{x^2+2}{y-5} + \frac{2}{5-y} = \frac{x^2+2}{y-5} - \frac{2}{y-5} = \frac{x^2+2-2}{y-5} = \frac{x^2}{y-5}$$
Ответ: $$\frac{x^2}{y-5}$$