3. Найдите значение выражений. a) 5 3/8 + 6 1/8; б) 6 9/16 + 3 11/16; в) 10 9/13 - 3 3/13; г) 18 2/5 - 5 3/5; д) 5/9 * 18/35; e) 3 1/9 * 2 2/7; ж) 8/15 : 16/25; з) 3 3/5 : 2 3/10

a) \( 5 \frac{3}{8} + 6 \frac{1}{8} = (5 + 6) + (\frac{3}{8} + \frac{1}{8}) = 11 + \frac{4}{8} = 11 \frac{1}{2} \) б) \( 6 \frac{9}{16} + 3 \frac{11}{16} = (6 + 3) + (\frac{9}{16} + \frac{11}{16}) = 9 + \frac{20}{16} = 9 + 1 \frac{4}{16} = 10 \frac{1}{4} \) в) \( 10 \frac{9}{13} - 3 \frac{3}{13} = (10 - 3) + (\frac{9}{13} - \frac{3}{13}) = 7 + \frac{6}{13} = 7 \frac{6}{13} \) г) \( 18 \frac{2}{5} - 5 \frac{3}{5} = 17 \frac{7}{5} - 5 \frac{3}{5} = (17 - 5) + (\frac{7}{5} - \frac{3}{5}) = 12 + \frac{4}{5} = 12 \frac{4}{5} \) д) \( \frac{5}{9} \cdot \frac{18}{35} = \frac{5 \cdot 18}{9 \cdot 35} = \frac{5 \cdot 2 \cdot 9}{9 \cdot 5 \cdot 7} = \frac{2}{7} \) e) \( 3 \frac{1}{9} \cdot 2 \frac{2}{7} = \frac{28}{9} \cdot \frac{16}{7} = \frac{4 \cdot 7 \cdot 16}{9 \cdot 7} = \frac{64}{9} = 7 \frac{1}{9} \) ж) \( \frac{8}{15} : \frac{16}{25} = \frac{8}{15} \cdot \frac{25}{16} = \frac{8 \cdot 25}{15 \cdot 16} = \frac{8 \cdot 5 \cdot 5}{3 \cdot 5 \cdot 2 \cdot 8} = \frac{5}{6} \) з) \( 3 \frac{3}{5} : 2 \frac{3}{10} = \frac{18}{5} : \frac{23}{10} = \frac{18}{5} \cdot \frac{10}{23} = \frac{18 \cdot 10}{5 \cdot 23} = \frac{18 \cdot 2 \cdot 5}{5 \cdot 23} = \frac{36}{23} = 1 \frac{13}{23} \) Ответы: a) \(11 \frac{1}{2}\) б) \(10 \frac{1}{4}\) в) \(7 \frac{6}{13}\) г) \(12 \frac{4}{5}\) д) \(\frac{2}{7}\) e) \(7 \frac{1}{9}\) ж) \(\frac{5}{6}\) з) \(1 \frac{13}{23}\)