1) \(\frac{2}{3} + \frac{5}{8}\) 2) \(\frac{7}{12} - \frac{3}{8}\) 3) \(\frac{11}{16} - \frac{5}{8}\) 4) \(\frac{6}{35} + \frac{3}{10}\) 5) \(\frac{8}{15} - \frac{4}{9}\) 6) \(\frac{4}{15} + \frac{7}{12}\) 7) \(\frac{11}{48} - \frac{5}{36}\) 8) \(\frac{4}{5} - \frac{2}{3} + \frac{4}{15}\) 9) \(\frac{7}{8} + \frac{11}{12} - \frac{5}{6}\)

Решение:

1. \( \frac{2}{3} + \frac{5}{8} = \frac{2 \times 8 + 5 \times 3}{24} = \frac{16 + 15}{24} = \frac{31}{24} = 1 \frac{7}{24} \)


2. \( \frac{7}{12} - \frac{3}{8} = \frac{7 \times 2 - 3 \times 3}{24} = \frac{14 - 9}{24} = \frac{5}{24} \)


3. \( \frac{11}{16} - \frac{5}{8} = \frac{11 - 5 \times 2}{16} = \frac{11 - 10}{16} = \frac{1}{16} \)


4. \( \frac{6}{35} + \frac{3}{10} = \frac{6 \times 2 + 3 \times 7}{70} = \frac{12 + 21}{70} = \frac{33}{70} \)


5. \( \frac{8}{15} - \frac{4}{9} = \frac{8 \times 3 - 4 \times 5}{45} = \frac{24 - 20}{45} = \frac{4}{45} \)


6. \( \frac{4}{15} + \frac{7}{12} = \frac{4 \times 4 + 7 \times 5}{60} = \frac{16 + 35}{60} = \frac{51}{60} = \frac{17}{20} \)


7. \( \frac{11}{48} - \frac{5}{36} = \frac{11 \times 3 - 5 \times 4}{144} = \frac{33 - 20}{144} = \frac{13}{144} \)


8. \( \frac{4}{5} - \frac{2}{3} + \frac{4}{15} = \frac{4 \times 3 - 2 \times 5 + 4}{15} = \frac{12 - 10 + 4}{15} = \frac{6}{15} = \frac{2}{5} \)


9. \( \frac{7}{8} + \frac{11}{12} - \frac{5}{6} = \frac{7 \times 3 + 11 \times 2 - 5 \times 4}{24} = \frac{21 + 22 - 20}{24} = \frac{23}{24} \)