ф) $$2\frac{1}{2} - 7\frac{5}{6}$$

$$2\frac{1}{2} - 7\frac{5}{6} = \frac{5}{2} - \frac{47}{6} = \frac{5 \cdot 3}{2 \cdot 3} - \frac{47}{6} = \frac{15}{6} - \frac{47}{6} = \frac{15-47}{6} = \frac{-32}{6} = -\frac{16}{3} = -5\frac{1}{3}$$ Ответ: $$-5\frac{1}{3}$$