Решим данные примеры:
a) \(\frac{2}{9} + \frac{6}{9} - \frac{3}{9} = \frac{2+6-3}{9} = \frac{5}{9}\)
Ответ: \(\frac{5}{9}\)
б) \(2 \frac{7}{13} + 3 \frac{8}{13} = (2+3) + (\frac{7}{13} + \frac{8}{13}) = 5 + \frac{15}{13} = 5 + \frac{13}{13} + \frac{2}{13} = 5 + 1 + \frac{2}{13} = 6 \frac{2}{13}\)
Ответ: \(6 \frac{2}{13}\)
в) \(6 - 2 \frac{5}{9} = 5 \frac{9}{9} - 2 \frac{5}{9} = (5-2) + (\frac{9}{9} - \frac{5}{9}) = 3 + \frac{4}{9} = 3 \frac{4}{9}\)
Ответ: \(3 \frac{4}{9}\)
г) \(8 \frac{2}{7} - 3 \frac{5}{7} = 7 \frac{9}{7} - 3 \frac{5}{7} = (7-3) + (\frac{9}{7} - \frac{5}{7}) = 4 + \frac{4}{7} = 4 \frac{4}{7}\)
Ответ: \(4 \frac{4}{7}\)