Вариант 2. Задание 5: Решите уравнение: 1) 5 8/21 - x = 2 9/14; 2) (x + 3/16) - 1/5 = 11/20

1) \(5 \frac{8}{21} - x = 2 \frac{9}{14}\) Чтобы решить уравнение, выразим x: \(x = 5 \frac{8}{21} - 2 \frac{9}{14}\) \(x = 5 + \frac{8}{21} - 2 - \frac{9}{14} = 3 + \frac{8 \cdot 2}{21 \cdot 2} - \frac{9 \cdot 3}{14 \cdot 3} = 3 + \frac{16}{42} - \frac{27}{42} = 3 - \frac{11}{42} = 2 \frac{31}{42}\) 2) \((x + \frac{3}{16}) - \frac{1}{5} = \frac{11}{20}\) \(x + \frac{3}{16} = \frac{11}{20} + \frac{1}{5}\) \(x + \frac{3}{16} = \frac{11}{20} + \frac{1 \cdot 4}{5 \cdot 4} = \frac{11}{20} + \frac{4}{20} = \frac{15}{20} = \frac{3}{4}\) \(x = \frac{3}{4} - \frac{3}{16}\) \(x = \frac{3 \cdot 4}{4 \cdot 4} - \frac{3}{16} = \frac{12}{16} - \frac{3}{16} = \frac{9}{16}\)