Вычислите: 5 + 2 3/8; 5 3/7 − 1 4/7; 12 8/15 − 12; 4 5/11 − 2 8/11; 3 8/11 + 5 2/11; 4 − 7/9; 9 7/12 − 7 6/12; 8 − 3 7/13; 4 3/5 + 2 4/5.

1. \(5+2\frac{3}{8}=7\frac{3}{8}\).
2. \(5\frac{3}{7}-1\frac{4}{7}=4\frac{10}{7}-1\frac{4}{7}=3\frac{6}{7}\).
3. \(12\frac{8}{15}-12=\frac{8}{15}\).
4. \(4\frac{5}{11}-2\frac{8}{11}=3\frac{16}{11}-2\frac{8}{11}=1\frac{8}{11}\).
5. \(3\frac{8}{11}+5\frac{2}{11}=8\frac{10}{11}\).
6. \(4-\frac{7}{9}=3\frac{9}{9}-\frac{7}{9}=3\frac{2}{9}\).
7. \(9\frac{7}{12}-7\frac{6}{12}=2\frac{1}{12}\).
8. \(8-3\frac{7}{13}=7\frac{13}{13}-3\frac{7}{13}=4\frac{6}{13}\).
9. \(4\frac{3}{5}+2\frac{4}{5}=6\frac{7}{5}=7\frac{2}{5}\).

Ответ: \(7\frac{3}{8};\ 3\frac{6}{7};\ \frac{8}{15};\ 1\frac{8}{11};\ 8\frac{10}{11};\ 3\frac{2}{9};\ 2\frac{1}{12};\ 4\frac{6}{13};\ 7\frac{2}{5}\).