a) -3/7 + 6/7 = b) -5/11 + 3/11 = c) 3/4 + (-1/6) = d) -1 + 4/7 = e) -4 + 2 7/8 = f) 10 + (-8 5/13) g) 8 2/7 ÷ (-4 5/14) = h) -9 1/2 + 8,5 =

Решение:

1. a) $$-\frac{3}{7} + \frac{6}{7} = \frac{-3+6}{7} = \frac{3}{7}$$
   Ответ: $$\frac{3}{7}$$
2. b) $$-\frac{5}{11} + \frac{3}{11} = \frac{-5+3}{11} = -\frac{2}{11}$$
   Ответ: $$-\frac{2}{11}$$
3. c) $$\frac{3}{4} + (-\frac{1}{6}) = \frac{3}{4} - \frac{1}{6} = \frac{3 \cdot 3}{4 \cdot 3} - \frac{1 \cdot 2}{6 \cdot 2} = \frac{9}{12} - \frac{2}{12} = \frac{9-2}{12} = \frac{7}{12}$$
   Ответ: $$\frac{7}{12}$$
4. d) $$-1 + \frac{4}{7} = -\frac{7}{7} + \frac{4}{7} = \frac{-7+4}{7} = -\frac{3}{7}$$
   Ответ: $$\frac{-3}{7}$$
5. e) $$-4 + 2\frac{7}{8} = -4 + \frac{2 \cdot 8 + 7}{8} = -4 + \frac{16+7}{8} = -4 + \frac{23}{8} = -\frac{4 \cdot 8}{8} + \frac{23}{8} = -\frac{32}{8} + \frac{23}{8} = \frac{-32+23}{8} = -\frac{9}{8} = -1\frac{1}{8}$$
   Ответ: $$-1\frac{1}{8}$$
6. f) $$10 + (-8\frac{5}{13}) = 10 - 8\frac{5}{13} = 10 - \frac{8 \cdot 13 + 5}{13} = 10 - \frac{104+5}{13} = 10 - \frac{109}{13} = \frac{10 \cdot 13}{13} - \frac{109}{13} = \frac{130}{13} - \frac{109}{13} = \frac{130-109}{13} = \frac{21}{13} = 1\frac{8}{13}$$
   Ответ: $$1\frac{8}{13}$$
7. g) $$8\frac{2}{7} \div (-4\frac{5}{14}) = \frac{8 \cdot 7 + 2}{7} \div (-\frac{4 \cdot 14 + 5}{14}) = \frac{56+2}{7} \div (-\frac{56+5}{14}) = \frac{58}{7} \div (-\frac{61}{14}) = \frac{58}{7} \cdot (-\frac{14}{61}) = -\frac{58 \cdot 14}{7 \cdot 61} = -\frac{58 \cdot 2}{61} = -\frac{116}{61} = -1\frac{55}{61}$$
   Ответ: $$-1\frac{55}{61}$$
8. h) $$-9\frac{1}{2} + 8.5 = -9.5 + 8.5 = -1$$
   Ответ: $$-1$$