x) $$-4\frac{2}{3} - 7\frac{7}{9}$$

$$-4\frac{2}{3} - 7\frac{7}{9} = -\frac{14}{3} - \frac{70}{9} = -\frac{14 \cdot 3}{3 \cdot 3} - \frac{70}{9} = -\frac{42}{9} - \frac{70}{9} = \frac{-42-70}{9} = \frac{-112}{9} = -12\frac{4}{9}$$ Ответ: $$-12\frac{4}{9}$$