Вычисли значения выражений из карточек №4 и №5

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