160. Выполните действия: а) (3 7/30 - 1 5/12) : 18 1/6 б) (1 1/2 + 2 2/3) : 1 2/3 в) (11/18 - 1 7/12) • (2 1/6 + 7/30) г) (3 2/5 - 5) • (31/48 + 7/24)

Решение примеров по действиям: а) $(3 \frac{7}{30} - 1 \frac{5}{12}) : 18 \frac{1}{6}$ 1. $3 \frac{7}{30} - 1 \frac{5}{12} = 3 \frac{14}{60} - 1 \frac{25}{60} = 2 \frac{74}{60} - 1 \frac{25}{60} = 1 \frac{49}{60} = \frac{109}{60}$ 2. $\frac{109}{60} : 18 \frac{1}{6} = \frac{109}{60} : \frac{109}{6} = \frac{109}{60} \cdot \frac{6}{109} = \frac{1}{10} = 0,1$ Ответ: 0,1 б) $(1 \frac{1}{2} + 2 \frac{2}{3}) : 1 \frac{2}{3}$ 1. $1 \frac{1}{2} + 2 \frac{2}{3} = 1 \frac{3}{6} + 2 \frac{4}{6} = 3 \frac{7}{6} = 4 \frac{1}{6} = \frac{25}{6}$ 2. $\frac{25}{6} : 1 \frac{2}{3} = \frac{25}{6} : \frac{5}{3} = \frac{25}{6} \cdot \frac{3}{5} = \frac{5}{2} = 2,5$ Ответ: 2,5 в) $(\frac{11}{18} - 1 \frac{7}{12}) \cdot (2 \frac{1}{6} + \frac{7}{30})$ 1. $\frac{11}{18} - 1 \frac{7}{12} = \frac{22}{36} - 1 \frac{21}{36} = -\frac{35}{36}$ 2. $2 \frac{1}{6} + \frac{7}{30} = 2 \frac{5}{30} + \frac{7}{30} = 2 \frac{12}{30} = 2 \frac{2}{5} = \frac{12}{5}$ 3. $-\frac{35}{36} \cdot \frac{12}{5} = -\frac{7 \cdot 1}{3 \cdot 1} = -\frac{7}{3} = -2 \frac{1}{3}$ Ответ: $-2 \frac{1}{3}$ г) $(3 \frac{2}{5} - 5) \cdot (\frac{31}{48} + \frac{7}{24})$ 1. $3 \frac{2}{5} - 5 = -1 \frac{3}{5} = -\frac{8}{5}$ 2. $\frac{31}{48} + \frac{7}{24} = \frac{31}{48} + \frac{14}{48} = \frac{45}{48} = \frac{15}{16}$ 3. $-\frac{8}{5} \cdot \frac{15}{16} = -\frac{1 \cdot 3}{1 \cdot 2} = -\frac{3}{2} = -1,5$ Ответ: -1,5