47. Вычислите: 1) 5/7 + 1/4; 2) 7/15 - 3/10; 3) 11/18 - 4/9; 4) 7/30 + 9/20; 5) 11/16 - 5/12; 6) 5/18 + 4/27; 7) 19/42 - 3/28; 8) 8/9 - 5/6 + 1/3; 9) 9/16 + 5/6 - 7/24.

1) \(\frac{5}{7} + \frac{1}{4} = \frac{20}{28} + \frac{7}{28} = \frac{27}{28}\) 2) \(\frac{7}{15} - \frac{3}{10} = \frac{14}{30} - \frac{9}{30} = \frac{5}{30} = \frac{1}{6}\) 3) \(\frac{11}{18} - \frac{4}{9} = \frac{11}{18} - \frac{8}{18} = \frac{3}{18} = \frac{1}{6}\) 4) \(\frac{7}{30} + \frac{9}{20} = \frac{14}{60} + \frac{27}{60} = \frac{41}{60}\) 5) \(\frac{11}{16} - \frac{5}{12} = \frac{33}{48} - \frac{20}{48} = \frac{13}{48}\) 6) \(\frac{5}{18} + \frac{4}{27} = \frac{15}{54} + \frac{8}{54} = \frac{23}{54}\) 7) \(\frac{19}{42} - \frac{3}{28} = \frac{38}{84} - \frac{9}{84} = \frac{29}{84}\) 8) \(\frac{8}{9} - \frac{5}{6} + \frac{1}{3} = \frac{16}{18} - \frac{15}{18} + \frac{6}{18} = \frac{7}{18}\) 9) \(\frac{9}{16} + \frac{5}{6} - \frac{7}{24} = \frac{27}{48} + \frac{40}{48} - \frac{14}{48} = \frac{53}{48}\)