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