5.300 б) $$17\frac{5}{14} - 5\frac{3}{14} = (17 - 5) + (\frac{5}{14} - \frac{3}{14}) = 12 + \frac{2}{14} = 12 + \frac{1}{7} = 12\frac{1}{7}$$
5.301 б) $$12 +19\frac{5}{24} = 31\frac{5}{24}$$
Ответ: 5.300 б) $$12\frac{1}{7}$$; 5.301 б) $$31\frac{5}{24}$$