Ответ: Смотри решение ниже
\[ 5 \cdot \left(\frac{3}{4} + \frac{11}{8}\right) = 5 \cdot \left(\frac{6}{8} + \frac{11}{8}\right) = 5 \cdot \frac{17}{8} = \frac{85}{8} = 10 \frac{5}{8} \]
\[ \frac{18}{7} \cdot \left(\frac{4}{9} + \frac{15}{18}\right) = \frac{18}{7} \cdot \left(\frac{8}{18} + \frac{15}{18}\right) = \frac{18}{7} \cdot \frac{23}{18} = \frac{23}{7} = 3 \frac{2}{7} \]
\[ \frac{8}{5} \cdot \frac{3}{4} + \frac{11}{8} = \frac{6}{5} + \frac{11}{8} = \frac{48}{40} + \frac{55}{40} = \frac{103}{40} = 2 \frac{23}{40} \]
\[ \frac{18}{7} \cdot \frac{4}{9} + \frac{15}{14} = \frac{8}{7} + \frac{15}{14} = \frac{16}{14} + \frac{15}{14} = \frac{31}{14} = 2 \frac{3}{14} \]
\[ 15 \cdot \left(1 + \frac{1}{3} - \frac{1}{5}\right) = 15 \cdot \left(\frac{15}{15} + \frac{5}{15} - \frac{3}{15}\right) = 15 \cdot \frac{17}{15} = 17 \]
\[ 72 \cdot \left(\frac{19}{24} - \frac{7}{12} + \frac{3}{8}\right) = 72 \cdot \left(\frac{19}{24} - \frac{14}{24} + \frac{9}{24}\right) = 72 \cdot \frac{14}{24} = 3 \cdot 14 = 42 \]
\[ \frac{72}{73} + \frac{34}{65} = \frac{72 \cdot 65 + 34 \cdot 73}{73 \cdot 65} = \frac{4680 + 2482}{4745} = \frac{7162}{4745} = 1 \frac{2417}{4745} \]
\[ \frac{107}{89} + \frac{64}{70} = \frac{107 \cdot 70 + 64 \cdot 89}{89 \cdot 70} = \frac{7490 + 5696}{6230} = \frac{13186}{6230} = \frac{6593}{3115} = 2 \frac{363}{3115} \]
\[ \frac{45}{46} - \frac{49}{45} + \frac{3}{1} = \frac{45 \cdot 45 - 49 \cdot 46 + 3 \cdot 46 \cdot 45}{46 \cdot 45} = \frac{2025 - 2254 + 6210}{2070} = \frac{5981}{2070} = 2 \frac{1841}{2070} \]
Ответ: Смотри решение выше