Задание 3: Вычислите: 1) 3/10 + 5/12; 2) 13/24 - 7/16; 3) 1 4/15 + 3 7/25; 4) 9 11/12 - 5 3/8

Решение: 1) \(\frac{3}{10} + \frac{5}{12} = \frac{3 \cdot 6}{10 \cdot 6} + \frac{5 \cdot 5}{12 \cdot 5} = \frac{18}{60} + \frac{25}{60} = \frac{43}{60}\) 2) \(\frac{13}{24} - \frac{7}{16} = \frac{13 \cdot 2}{24 \cdot 2} - \frac{7 \cdot 3}{16 \cdot 3} = \frac{26}{48} - \frac{21}{48} = \frac{5}{48}\) 3) \(1 \frac{4}{15} + 3 \frac{7}{25} = 1 + \frac{4}{15} + 3 + \frac{7}{25} = 4 + \frac{4}{15} + \frac{7}{25} = 4 + \frac{4 \cdot 5}{15 \cdot 5} + \frac{7 \cdot 3}{25 \cdot 3} = 4 + \frac{20}{75} + \frac{21}{75} = 4 + \frac{41}{75} = 4 \frac{41}{75}\) 4) \(9 \frac{11}{12} - 5 \frac{3}{8} = 9 + \frac{11}{12} - (5 + \frac{3}{8}) = 9 + \frac{11}{12} - 5 - \frac{3}{8} = 4 + \frac{11}{12} - \frac{3}{8} = 4 + \frac{11 \cdot 2}{12 \cdot 2} - \frac{3 \cdot 3}{8 \cdot 3} = 4 + \frac{22}{24} - \frac{9}{24} = 4 + \frac{13}{24} = 4 \frac{13}{24}\)