Вычисли выражения с дробями из карточек №4, №5 и №6

Карточка №4 1) $\frac{4}{5} + \frac{3}{7} = \frac{4 * 7 + 3 * 5}{5 * 7} = \frac{28 + 15}{35} = \frac{43}{35}$ 2) $\frac{5}{9} - \frac{7}{18} = \frac{5 * 2 - 7}{18} = \frac{10 - 7}{18} = \frac{3}{18} = \frac{1}{6}$ 3) $\frac{5}{21} + \frac{5}{28} = \frac{5 * 4 + 5 * 3}{84} = \frac{20 + 15}{84} = \frac{35}{84} = \frac{5}{12}$ 4) $\frac{15}{19} + \frac{27}{38} = \frac{15 * 2 + 27}{38} = \frac{30 + 27}{38} = \frac{57}{38}$ 5) $\frac{7}{18} - \frac{1}{5} + \frac{1}{9} = \frac{7 * 5 - 18 * 1 + 1 * 10}{90} = \frac{35 - 18 + 10}{90} = \frac{27}{90} = \frac{3}{10}$ Карточка №5 1) $\frac{9}{16} + \frac{19}{24} = \frac{9 * 3 + 19 * 2}{48} = \frac{27 + 38}{48} = \frac{65}{48}$ 2) $\frac{13}{60} - \frac{7}{40} = \frac{13 * 2 - 7 * 3}{120} = \frac{26 - 21}{120} = \frac{5}{120} = \frac{1}{24}$ 3) $\frac{11}{42} - \frac{5}{28} = \frac{11 * 2 - 5 * 3}{84} = \frac{22 - 15}{84} = \frac{7}{84} = \frac{1}{12}$ 4) $\frac{9}{20} + \frac{5}{12} = \frac{9 * 3 + 5 * 5}{60} = \frac{27 + 25}{60} = \frac{52}{60} = \frac{13}{15}$ 5) $\frac{7}{15} - \frac{1}{6} - \frac{1}{10} = \frac{7 * 2 - 5 - 3}{30} = \frac{14 - 5 - 3}{30} = \frac{6}{30} = \frac{1}{5}$ Карточка №6 1) $\frac{2}{7} - \frac{5}{42} = \frac{2 * 6 - 5}{42} = \frac{12 - 5}{42} = \frac{7}{42} = \frac{1}{6}$ 2) $\frac{1}{11} + \frac{1}{33} = \frac{3 + 1}{33} = \frac{4}{33}$ 3) $\frac{5}{12} + \frac{5}{18} = \frac{5 * 3 + 5 * 2}{36} = \frac{15 + 10}{36} = \frac{25}{36}$ 4) $\frac{4}{35} + \frac{1}{28} = \frac{4 * 4 + 5}{140} = \frac{16 + 5}{140} = \frac{21}{140} = \frac{3}{20}$ 5) $\frac{19}{20} - \frac{3}{8} - \frac{1}{5} = \frac{19 * 2 - 3 * 5 - 1 * 8}{40} = \frac{38 - 15 - 8}{40} = \frac{15}{40} = \frac{3}{8}$