Выполните сложение: а) -3/7 + 6/7; б) -5/11 + 3/11; в) 3/4 + (-1/6); г) -1 + 4/7; д) -4 + 2 7/8; е) 10 + (-8 5/13); ж) 8 2/7 + (-7 5/14); з) -9 1/7 + 8,5.

**Ответ:** а) $-\frac{3}{7} + \frac{6}{7} = \frac{6 - 3}{7} = \frac{3}{7}$ б) $-\frac{5}{11} + \frac{3}{11} = \frac{-5 + 3}{11} = -\frac{2}{11}$ в) $\frac{3}{4} + (-\frac{1}{6}) = \frac{3 \cdot 3}{12} - \frac{1 \cdot 2}{12} = \frac{9 - 2}{12} = \frac{7}{12}$ г) $-1 + \frac{4}{7} = -\frac{7}{7} + \frac{4}{7} = -\frac{3}{7}$ д) $-4 + 2\frac{7}{8} = -(4 - 2\frac{7}{8}) = -(3\frac{8}{8} - 2\frac{7}{8}) = -1\frac{1}{8}$ е) $10 + (-8\frac{5}{13}) = 10 - 8\frac{5}{13} = 9\frac{13}{13} - 8\frac{5}{13} = 1\frac{8}{13}$ ж) $8\frac{2}{7} + (-7\frac{5}{14}) = 8\frac{4}{14} - 7\frac{5}{14} = 7\frac{18}{14} - 7\frac{5}{14} = \frac{13}{14}$ з) $-9\frac{1}{7} + 8,5 = -9\frac{1}{7} + 8\frac{1}{2} = -9\frac{2}{14} + 8\frac{7}{14} = -(9\frac{2}{14} - 8\frac{7}{14}) = -(8\frac{16}{14} - 8\frac{7}{14}) = -\frac{9}{14}$