Вычисли: а) 30/(5/12 + 1/4); б) (1 3/8 * 2)/11; в) (4 - 1 3/5)/(7 1/2 * 9/25); г) (8 1/3 : 2)/(1 9/10 + 4 7/20); д) (7 1/3 : 1 1/6) : (8 : 7) / (9 : (1 3/11 + 2)); е) (3 4/7 : (6 1/28 - 3 3/4)) / ((1 5/6 * 1 5/22) : 18 * 5).

Привет! Давай решим эти примеры на дроби. **а)** $\frac{30}{\frac{5}{12} + \frac{1}{4}} = \frac{30}{\frac{5}{12} + \frac{3}{12}} = \frac{30}{\frac{8}{12}} = \frac{30}{\frac{2}{3}} = 30 \cdot \frac{3}{2} = 45$ **б)** $\frac{1\frac{3}{8} \cdot 2}{11} = \frac{\frac{11}{8} \cdot 2}{11} = \frac{\frac{11}{4}}{11} = \frac{11}{4} \cdot \frac{1}{11} = \frac{1}{4} = 0,25$ **в)** $\frac{4 - 1\frac{3}{5}}{7\frac{1}{2} \cdot \frac{9}{25}} = \frac{2\frac{2}{5}}{\frac{15}{2} \cdot \frac{9}{25}} = \frac{\frac{12}{5}}{\frac{3}{2} \cdot \frac{9}{5}} = \frac{\frac{12}{5}}{\frac{27}{10}} = \frac{12}{5} \cdot \frac{10}{27} = \frac{4 \cdot 2}{9} = \frac{8}{9}$ **г)** $\frac{8\frac{1}{3} : 2}{1\frac{9}{10} + 4\frac{7}{20}} = \frac{\frac{25}{3} \cdot \frac{1}{2}}{\frac{19}{10} + \frac{87}{20}} = \frac{\frac{25}{6}}{\frac{38}{20} + \frac{87}{20}} = \frac{\frac{25}{6}}{\frac{125}{20}} = \frac{25}{6} : \frac{25}{4} = \frac{25}{6} \cdot \frac{4}{25} = \frac{4}{6} = \frac{2}{3}$ **д)** Числитель: $(7\frac{1}{3} : 1\frac{1}{6}) : (8 : 7) = (\frac{22}{3} : \frac{7}{6}) : \frac{8}{7} = (\frac{22}{3} \cdot \frac{6}{7}) : \frac{8}{7} = \frac{44}{7} : \frac{8}{7} = \frac{44}{8} = 5,5$. Знаменатель: $9 : (1\frac{3}{11} + 2) = 9 : (\frac{14}{11} + \frac{22}{11}) = 9 : \frac{36}{11} = 9 \cdot \frac{11}{36} = \frac{11}{4} = 2,75$. Итог: $5,5 : 2,75 = 2$. **е)** Числитель: $3\frac{4}{7} : (6\frac{1}{28} - 3\frac{3}{4}) = \frac{25}{7} : (\frac{169}{28} - \frac{105}{28}) = \frac{25}{7} : \frac{64}{28} = \frac{25}{7} : \frac{16}{7} = \frac{25}{16}$. Знаменатель: $(1\frac{5}{6} \cdot 1\frac{5}{22}) : 18 \cdot 5 = (\frac{11}{6} \cdot \frac{27}{22}) : 18 \cdot 5 = \frac{9}{4} : 18 \cdot 5 = (\frac{9}{4} \cdot \frac{1}{18}) \cdot 5 = \frac{1}{8} \cdot 5 = \frac{5}{8}$. Итог: $\frac{25}{16} : \frac{5}{8} = \frac{25}{16} \cdot \frac{8}{5} = \frac{5}{2} = 2,5$.