1) Вычислите: 3/4 + 2/3; 3/10 + 2/15; 4/5 + 1/6; 6/7 − 2/3; 11/12 − 5/6; 7/12 − 3/8; 1 − 5/8; 5 − 2/3; 8 − 4 7/8.

1. \(\frac{3}{4}+\frac{2}{3}=\frac{9}{12}+\frac{8}{12}=\frac{17}{12}=1\frac{5}{12}\).
2. \(\frac{3}{10}+\frac{2}{15}=\frac{9}{30}+\frac{4}{30}=\frac{13}{30}\).
3. \(\frac{4}{5}+\frac{1}{6}=\frac{24}{30}+\frac{5}{30}=\frac{29}{30}\).
4. \(\frac{6}{7}-\frac{2}{3}=\frac{18}{21}-\frac{14}{21}=\frac{4}{21}\).
5. \(\frac{11}{12}-\frac{5}{6}=\frac{11}{12}-\frac{10}{12}=\frac{1}{12}\).
6. \(\frac{7}{12}-\frac{3}{8}=\frac{14}{24}-\frac{9}{24}=\frac{5}{24}\).
7. \(1-\frac{5}{8}=\frac{8}{8}-\frac{5}{8}=\frac{3}{8}\).
8. \(5-\frac{2}{3}=4\frac{3}{3}-\frac{2}{3}=4\frac{1}{3}\).
9. \(8-4\frac{7}{8}=7\frac{8}{8}-4\frac{7}{8}=3\frac{1}{8}\).

Ответ: 1) \(1\frac{5}{12}\); 2) \(\frac{13}{30}\); 3) \(\frac{29}{30}\); 4) \(\frac{4}{21}\); 5) \(\frac{1}{12}\); 6) \(\frac{5}{24}\); 7) \(\frac{3}{8}\); 8) \(4\frac{1}{3}\); 9) \(3\frac{1}{8}\).