Вычислите удобным способом: $$1\frac{8}{13} + ( -6\frac{5}{7}) + 2\frac{5}{13} =$$

$$1\frac{8}{13} + ( -6\frac{5}{7}) + 2\frac{5}{13} = 1\frac{8}{13} + 2\frac{5}{13} - 6\frac{5}{7} = (1 + 2) + \frac{8+5}{13} - 6\frac{5}{7} = 3 + \frac{13}{13} - 6\frac{5}{7} = 3 + 1 - 6\frac{5}{7} = 4 - 6\frac{5}{7} = 4 - \frac{6 \cdot 7 + 5}{7} = 4 - \frac{47}{7} = \frac{4 \cdot 7}{7} - \frac{47}{7} = \frac{28 - 47}{7} = \frac{-19}{7} = -2\frac{5}{7}$$

Ответ: $$-2\frac{5}{7}$$