Вычислите: 12/17 * (11/24 - 3/8)

Привет! Давай решим примеры с дробями по порядку. 1) $\frac{12}{17} \cdot (\frac{11}{24} - \frac{3}{8}) = \frac{12}{17} \cdot (\frac{11}{24} - \frac{9}{24}) = \frac{12}{17} \cdot \frac{2}{24} = \frac{12 \cdot 2}{17 \cdot 24} = \frac{1}{17} \cdot 1 = \frac{1}{17}$. Ответ: 1/17 2) $\frac{21}{26} \cdot (\frac{7}{20} - \frac{2}{15}) = \frac{21}{26} \cdot (\frac{21}{60} - \frac{8}{60}) = \frac{21}{26} \cdot \frac{13}{60} = \frac{21 \cdot 13}{26 \cdot 60} = \frac{21}{2 \cdot 60} = \frac{7}{2 \cdot 20} = \frac{7}{40}$. Ответ: 7/40 3) $\frac{25}{27} \cdot \frac{10}{21} \cdot \frac{15}{28} = \frac{25 \cdot 10 \cdot 15}{27 \cdot 21 \cdot 28} = \frac{25 \cdot 10 \cdot 5}{9 \cdot 21 \cdot 28} = \frac{1250}{15876} = \frac{625}{7938}$. Ответ: 625/7938 4) $\frac{19}{32} - \frac{7}{22} : \frac{28}{33} = \frac{19}{32} - \frac{7}{22} \cdot \frac{33}{28} = \frac{19}{32} - \frac{1 \cdot 3}{2 \cdot 4} = \frac{19}{32} - \frac{3}{8} = \frac{19}{32} - \frac{12}{32} = \frac{7}{32}$. Ответ: 7/32 5) $\frac{14}{15} - \frac{14}{45} : \frac{7}{18} = \frac{14}{15} - \frac{14}{45} \cdot \frac{18}{7} = \frac{14}{15} - \frac{2}{5} \cdot 2 = \frac{14}{15} - \frac{4}{5} = \frac{14}{15} - \frac{12}{15} = \frac{2}{15}$. Ответ: 2/15 6) $18 \cdot \frac{5}{84} - \frac{17}{21} = \frac{18 \cdot 5}{84} - \frac{17}{21} = \frac{3 \cdot 5}{14} - \frac{17}{21} = \frac{15}{14} - \frac{17}{21} = \frac{45}{42} - \frac{34}{42} = \frac{11}{42}$. Ответ: 11/42 7) $14 \cdot \frac{3}{56} - \frac{13}{36} = \frac{14 \cdot 3}{56} - \frac{13}{36} = \frac{3}{4} - \frac{13}{36} = \frac{27}{36} - \frac{13}{36} = \frac{14}{36} = \frac{7}{18}$. Ответ: 7/18