2 5 2. 5--4-

2. $$5\frac{2}{7} - 4\frac{5}{7} = (5-4) + (\frac{2}{7} - \frac{5}{7}) = 1 - \frac{3}{7} = \frac{7}{7} - \frac{3}{7} = \frac{4}{7}$$
Ответ: $$\frac{4}{7}$$