Вычисли примеры: a) $$rac{4}{9} \times (18 \times \frac{7}{8})$$ b) $$(\frac{3}{5} \times 20) \times \frac{1}{4}$$ c) $$(12+\frac{2}{3}) \times 3$$ d) $$9 \times (8-\frac{3}{8})$$ e) $$(10-\frac{5}{12}) \times 12$$ f) $$(\frac{7}{10} \times 30) \times 2$$ g) $$\frac{2}{7} \times (14\times \frac{5}{6})$$ h) $$(5 + \frac{1}{2}) \times 8$$ i) $$(\frac{9}{11} \times 22) \times \frac{3}{2}$$ j) $$11 \times (6 - \frac{2}{3})$$ k) $$(15-\frac{3}{5}) \times 5$$ l) $$(\frac{4}{7} \times 21) \times \frac{3}{4}$$

Привет! Давай порешаем эти примеры с дробями и умножением. Главное, помни про порядок действий: сначала делаем то, что в скобках, а потом умножаем или делим. a) $$\frac{4}{9} \times (18 \times \frac{7}{8}) = \frac{4}{9} \times (\frac{18 \times 7}{8}) = \frac{4}{9} \times (\frac{9 \times 7}{4}) = \frac{4}{9} \times \frac{63}{4} = \frac{4 \times 63}{9 \times 4} = \frac{63}{9} = 7$$ b) $$(\frac{3}{5} \times 20) \times \frac{1}{4} = (\frac{3 \times 20}{5}) \times \frac{1}{4} = (3 \times 4) \times \frac{1}{4} = 12 \times \frac{1}{4} = \frac{12}{4} = 3$$ c) $$(12+\frac{2}{3}) \times 3 = (\frac{12 \times 3}{3} + \frac{2}{3}) \times 3 = (\frac{36}{3} + \frac{2}{3}) \times 3 = \frac{38}{3} \times 3 = 38$$ d) $$9 \times (8-\frac{3}{8}) = 9 \times (\frac{8 \times 8}{8} - \frac{3}{8}) = 9 \times (\frac{64}{8} - \frac{3}{8}) = 9 \times \frac{61}{8} = \frac{9 \times 61}{8} = \frac{549}{8} = 68\frac{5}{8}$$ e) $$(10-\frac{5}{12}) \times 12 = (\frac{10 \times 12}{12} - \frac{5}{12}) \times 12 = (\frac{120}{12} - \frac{5}{12}) \times 12 = \frac{115}{12} \times 12 = 115$$ f) $$(\frac{7}{10} \times 30) \times 2 = (\frac{7 \times 30}{10}) \times 2 = (7 \times 3) \times 2 = 21 \times 2 = 42$$ g) $$\frac{2}{7} \times (14\times \frac{5}{6}) = \frac{2}{7} \times (\frac{14 \times 5}{6}) = \frac{2}{7} \times (\frac{7 \times 5}{3}) = \frac{2}{7} \times \frac{35}{3} = \frac{2 \times 35}{7 \times 3} = \frac{2 \times 5 \times 7}{7 \times 3} = \frac{10}{3} = 3\frac{1}{3}$$ h) $$(5 + \frac{1}{2}) \times 8 = (\frac{5 \times 2}{2} + \frac{1}{2}) \times 8 = (\frac{10}{2} + \frac{1}{2}) \times 8 = \frac{11}{2} \times 8 = \frac{11 \times 8}{2} = 11 \times 4 = 44$$ i) $$(\frac{9}{11} \times 22) \times \frac{3}{2} = (\frac{9 \times 22}{11}) \times \frac{3}{2} = (9 \times 2) \times \frac{3}{2} = 18 \times \frac{3}{2} = \frac{18 \times 3}{2} = 9 \times 3 = 27$$ j) $$11 \times (6 - \frac{2}{3}) = 11 \times (\frac{6 \times 3}{3} - \frac{2}{3}) = 11 \times (\frac{18}{3} - \frac{2}{3}) = 11 \times \frac{16}{3} = \frac{11 \times 16}{3} = \frac{176}{3} = 58\frac{2}{3}$$ k) $$(15-\frac{3}{5}) \times 5 = (\frac{15 \times 5}{5} - \frac{3}{5}) \times 5 = (\frac{75}{5} - \frac{3}{5}) \times 5 = \frac{72}{5} \times 5 = 72$$ l) $$(\frac{4}{7} \times 21) \times \frac{3}{4} = (\frac{4 \times 21}{7}) \times \frac{3}{4} = (4 \times 3) \times \frac{3}{4} = 12 \times \frac{3}{4} = \frac{12 \times 3}{4} = 3 \times 3 = 9$$