45. Вычислите. а) (12/30 + 4/5) * 15/24 + 3/4 * 3 2/15 - 1 7/30 * 3/4

а) $\left(\frac{12}{30} + \frac{4}{5}\right) \cdot \frac{15}{24} + \frac{3}{4} \cdot 3\frac{2}{15} - 1\frac{7}{30} \cdot \frac{3}{4} = \left(\frac{2}{5} + \frac{4}{5}\right) \cdot \frac{5}{8} + \frac{3}{4} \cdot \frac{47}{15} - \frac{37}{30} \cdot \frac{3}{4} = \frac{6}{5} \cdot \frac{5}{8} + \frac{47}{20} - \frac{37}{40} = \frac{3}{4} + 2\frac{7}{20} - \frac{37}{40} = \frac{30}{40} + \frac{94}{40} - \frac{37}{40} = \frac{87}{40} = 2\frac{7}{40}$ б) $\left(\frac{2}{3} \cdot 3\frac{2}{15} + \frac{7}{45} : 1\frac{1}{2}\right) : \frac{1}{9} - 1\frac{7}{12} : \frac{3}{16} \cdot \frac{1}{2} \cdot 8\frac{1}{4} : 1\frac{5}{6} = \left(\frac{2}{3} \cdot \frac{47}{15} + \frac{7}{45} \cdot \frac{2}{3}\right) \cdot 9 - \frac{19}{12} \cdot \frac{16}{3} \cdot \frac{1}{2} \cdot \frac{33}{4} \cdot \frac{6}{11} = \left(\frac{94}{45} + \frac{14}{135}\right) \cdot 9 - \frac{19 \cdot 4}{3 \cdot 3} \cdot \frac{1}{2} \cdot \frac{3 \cdot 6}{4} = \left(\frac{282 + 14}{135}\right) \cdot 9 - \frac{19 \cdot 2}{9} \cdot \frac{18}{4} = \frac{296}{135} \cdot 9 - \frac{38}{9} \cdot \frac{9}{2} = \frac{296}{15} - 19 = 19\frac{11}{15} - 19 = \frac{11}{15}$ в) $\frac{5}{12} \cdot 3\frac{1}{3} + \left(1 - \frac{7}{12}\right) \cdot 2\frac{1}{4} + 2\frac{1}{60} : 2\frac{2}{5} = \frac{5}{12} \cdot \frac{10}{3} + \frac{5}{12} \cdot \frac{9}{4} + \frac{121}{60} \cdot \frac{5}{12} = \frac{25}{18} + \frac{15}{16} + \frac{121}{144} = \frac{200 + 135 + 121}{144} = \frac{456}{144} = \frac{19}{6} = 3\frac{1}{6}$ г) $\left(\frac{1}{3} + 4\frac{4}{5} : 1\frac{5}{7}\right) \cdot 2\frac{1}{7} - 7\frac{1}{7} \cdot \left(1 - \frac{2}{3} : \frac{5}{22} : 7\frac{1}{3}\right) = \left(\frac{1}{3} + \frac{24}{5} \cdot \frac{7}{12}\right) \cdot \frac{15}{7} - \frac{50}{7} \cdot \left(1 - \frac{2}{3} \cdot \frac{22}{5} \cdot \frac{3}{22}\right) = \left(\frac{1}{3} + \frac{14}{5}\right) \cdot \frac{15}{7} - \frac{50}{7} \cdot \left(1 - \frac{2}{5}\right) = \frac{5 + 42}{15} \cdot \frac{15}{7} - \frac{50}{7} \cdot \frac{3}{5} = \frac{47}{15} \cdot \frac{15}{7} - \frac{10 \cdot 3}{7} = \frac{47}{7} - \frac{30}{7} = \frac{17}{7} = 2\frac{3}{7}$ **Ответ:** а) $2\frac{7}{40}$; б) $\frac{11}{15}$; в) $3\frac{1}{6}$; г) $2\frac{3}{7}$.