Вариант 2. Задание 3: Вычислите: 1) 1/6 + 2/7; 2) 11/18 - 5/12; 3) 4 7/12 + 1 3/16; 4) 8 17/20 - 6 7/10

1) \(\frac{1}{6} + \frac{2}{7} = \frac{1 \cdot 7}{6 \cdot 7} + \frac{2 \cdot 6}{7 \cdot 6} = \frac{7}{42} + \frac{12}{42} = \frac{7 + 12}{42} = \frac{19}{42}\) 2) \(\frac{11}{18} - \frac{5}{12} = \frac{11 \cdot 2}{18 \cdot 2} - \frac{5 \cdot 3}{12 \cdot 3} = \frac{22}{36} - \frac{15}{36} = \frac{22 - 15}{36} = \frac{7}{36}\) 3) \(4 \frac{7}{12} + 1 \frac{3}{16} = 4 + \frac{7}{12} + 1 + \frac{3}{16} = 5 + \frac{7 \cdot 4}{12 \cdot 4} + \frac{3 \cdot 3}{16 \cdot 3} = 5 + \frac{28}{48} + \frac{9}{48} = 5 + \frac{37}{48} = 5 \frac{37}{48}\) 4) \(8 \frac{17}{20} - 6 \frac{7}{10} = 8 + \frac{17}{20} - 6 - \frac{7}{10} = 2 + \frac{17}{20} - \frac{7 \cdot 2}{10 \cdot 2} = 2 + \frac{17}{20} - \frac{14}{20} = 2 + \frac{3}{20} = 2 \frac{3}{20}\)