Вычислите: 1) 2/3 + 5/8; 2) 7/12 - 3/8; 3) 11/16 - 5/8; 4) 6/35 + 3/10; 5) 8/15 - 4/9; 6) 4/15 + 7/12; 7) 11/48 - 5/36; 8) 4/5 - 2/3 + 4/15; 9) 7/8 + 11/12 - 5/6.

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