5.281 Вычислите: в) 5 - 4 3/4 г) 7 5/7 + 4 1/7

в) $$5 - 4\frac{3}{4} = 5 - (4 + \frac{3}{4}) = (5-4) - \frac{3}{4} = 1 - \frac{3}{4} = \frac{4}{4} - \frac{3}{4} = \frac{1}{4}$$; г) $$7\frac{5}{7} + 4\frac{1}{7} = (7+4) + (\frac{5}{7} + \frac{1}{7}) = 11 + \frac{6}{7} = 11\frac{6}{7}$$