a) \(7\frac{3}{5} - 1\frac{2}{5} = (7-1) + (\frac{3}{5} - \frac{2}{5}) = 6 + \frac{3-2}{5} = 6 + \frac{1}{5} = 6\frac{1}{5}\)
б) \(28\frac{6}{13} - 7\frac{1}{13} = (28-7) + (\frac{6}{13} - \frac{1}{13}) = 21 + \frac{6-1}{13} = 21 + \frac{5}{13} = 21\frac{5}{13}\)
в) \(6 - \frac{2}{5} = 5\frac{5}{5} - \frac{2}{5} = 5 + \frac{5-2}{5} = 5 + \frac{3}{5} = 5\frac{3}{5}\)
г) \(21 - \frac{5}{9} = 20\frac{9}{9} - \frac{5}{9} = 20 + \frac{9-5}{9} = 20 + \frac{4}{9} = 20\frac{4}{9}\)
д) \(4\frac{1}{7} - 1\frac{4}{7} = 4\frac{1}{7} - 1\frac{4}{7} = 3\frac{8}{7} - 1\frac{4}{7} = (3-1) + (\frac{8}{7} - \frac{4}{7}) = 2 + \frac{8-4}{7} = 2 + \frac{4}{7} = 2\frac{4}{7}\)
e) \(12\frac{2}{5} - 1\frac{4}{5} = 12\frac{2}{5} - 1\frac{4}{5} = 11\frac{7}{5} - 1\frac{4}{5} = (11-1) + (\frac{7}{5} - \frac{4}{5}) = 10 + \frac{7-4}{5} = 10 + \frac{3}{5} = 10\frac{3}{5}\)