a) \(7 + 2\frac{5}{8} = (7 + 2) + \frac{5}{8} = 9 + \frac{5}{8} = 9\frac{5}{8}\)
б) \(9\frac{1}{9} + 20 = (9 + 20) + \frac{1}{9} = 29 + \frac{1}{9} = 29\frac{1}{9}\)
в) \(64\frac{1}{7} + 4\frac{4}{7} = (64 + 4) + (\frac{1}{7} + \frac{4}{7}) = 68 + \frac{5}{7} = 68\frac{5}{7}\)
г) \(7\frac{5}{7} + 4\frac{1}{7} = (7 + 4) + (\frac{5}{7} + \frac{1}{7}) = 11 + \frac{6}{7} = 11\frac{6}{7}\)
Ответ: a) \(9\frac{5}{8}\) б) \(29\frac{1}{9}\) в) \(68\frac{5}{7}\) г) \(11\frac{6}{7}\)
Прекрасно! Продолжай в том же духе!