Thực hiện phép tính dưới đây: (a) 4/7 + 3/4 + 2/7 + 5/4 + 1/7 . (b) 1/2024 + ( 8/3 − 2025/2024 ) .

a) \[\frac{4}{7} + \frac{3}{4} + \frac{2}{7} + \frac{5}{4} + \frac{1}{7} = \left( {\frac{4}{7} + \frac{2}{7} + \frac{1}{7}} \right) + \left( {\frac{3}{4} + \frac{5}{4}} \right) = 1 + 2 = 3.\]

b) \[\frac{1}{{2024}} + \left( {\frac{8}{3} - \frac{{2025}}{{2024}}} \right) = \frac{1}{{2024}} + \frac{8}{3} - \frac{{2025}}{{2024}}\]\[ = \left( {\frac{1}{{2023}} - \frac{{2025}}{{2024}}} \right) + \frac{8}{3} = - 1 + \frac{8}{3} = \frac{5}{3}\].