6. Вычислите: 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} + \(\frac{11}{12} - \frac{5}{6}\).

1) \(\frac{2}{3} + \frac{5}{8} = \frac{2 \cdot 8 + 5 \cdot 3}{24} = \frac{16 + 15}{24} = \frac{31}{24}\). 2) \(\frac{7}{12} - \frac{3}{8} = \frac{7 \cdot 2 - 3 \cdot 3}{24} = \frac{14 - 9}{24} = \frac{5}{24}\). 3) \(\frac{11}{16} - \frac{5}{8} = \frac{11 - 5 \cdot 2}{16} = \frac{11 - 10}{16} = \frac{1}{16}\). 4) \(\frac{6}{35} + \frac{3}{10} = \frac{6 \cdot 2 + 3 \cdot 7}{70} = \frac{12 + 21}{70} = \frac{33}{70}\). 5) \(\frac{8}{15} - \frac{4}{9} = \frac{8 \cdot 3 - 4 \cdot 5}{45} = \frac{24 - 20}{45} = \frac{4}{45}\). 6) \(\frac{4}{15} + \frac{7}{12} = \frac{4 \cdot 4 + 7 \cdot 5}{60} = \frac{16 + 35}{60} = \frac{51}{60} = \frac{17}{20}\). 7) \(\frac{11}{48} - \frac{5}{36} = \frac{11 \cdot 3 - 5 \cdot 4}{144} = \frac{33 - 20}{144} = \frac{13}{144}\). 8) \(\frac{4}{5} - \frac{2}{3} + \frac{4}{15} = \frac{4 \cdot 3 - 2 \cdot 5 + 4}{15} = \frac{12 - 10 + 4}{15} = \frac{6}{15} = \frac{2}{5}\). 9) \(\frac{7}{8} + \frac{11}{12} - \frac{5}{6} = \frac{7 \cdot 3 + 11 \cdot 2 - 5 \cdot 4}{24} = \frac{21 + 22 - 20}{24} = \frac{23}{24}\).