5.300 Найдите разность: a) 139 4; 6) 17-5; B) 9 - 3윽; 14 3 14' 3 г) 100 - 20

a) $$13\frac{8}{9} - 4 = \frac{13 \cdot 9 + 8}{9} - 4 = \frac{117 + 8}{9} - 4 = \frac{125}{9} - \frac{4 \cdot 9}{9} = \frac{125}{9} - \frac{36}{9} = \frac{125 - 36}{9} = \frac{89}{9} = 9\frac{8}{9}$$

Ответ: $$9\frac{8}{9}$$

б) $$17\frac{5}{14} - 5\frac{3}{14} = (17 - 5) + (\frac{5}{14} - \frac{3}{14}) = 12 + \frac{5-3}{14} = 12 + \frac{2}{14} = 12 + \frac{1}{7} = 12\frac{1}{7}$$

Ответ: $$12\frac{1}{7}$$

в) $$9\frac{5}{7} - 3\frac{6}{7} = (9-3) + (\frac{5}{7} - \frac{6}{7}) = 6 - \frac{1}{7} = 5\frac{7}{7} - \frac{1}{7} = 5\frac{6}{7}$$

Ответ: $$5\frac{6}{7}$$

г) $$100 - 20\frac{3}{14} = 99\frac{14}{14} - 20\frac{3}{14} = (99 - 20) + (\frac{14}{14} - \frac{3}{14}) = 79 + \frac{11}{14} = 79\frac{11}{14}$$

Ответ: $$79\frac{11}{14}$$