Вычислите: 14. 24/49 : 6/7 + 1/14; 15. 5/6 - 4/9 : 16/21; 16. 8/9 - 3/8 : 27/28; 17. 16/21 : 12/35 - 2; 18. 35/24 : 15/32 - 3; 19. 2 - 15/28 : 10/21.

14. $\frac{24}{49} : \frac{6}{7} + \frac{1}{14} = \frac{24}{49} \cdot \frac{7}{6} + \frac{1}{14} = \frac{4}{7} + \frac{1}{14} = \frac{8}{14} + \frac{1}{14} = \frac{9}{14}$ Ответ: $\frac{9}{14}$. 15. $\frac{5}{6} - \frac{4}{9} : \frac{16}{21} = \frac{5}{6} - \frac{4}{9} \cdot \frac{21}{16} = \frac{5}{6} - \frac{7}{12} = \frac{10}{12} - \frac{7}{12} = \frac{3}{12} = \frac{1}{4}$ Ответ: $0,25$ (или $\frac{1}{4}$). 16. $\frac{8}{9} - \frac{3}{8} : \frac{27}{28} = \frac{8}{9} - \frac{3}{8} \cdot \frac{28}{27} = \frac{8}{9} - \frac{7}{18} = \frac{16}{18} - \frac{7}{18} = \frac{9}{18} = \frac{1}{2}$ Ответ: $0,5$ (или $\frac{1}{2}$). 17. $\frac{16}{21} : \frac{12}{35} - 2 = \frac{16}{21} \cdot \frac{35}{12} - 2 = \frac{4 \cdot 5}{3 \cdot 3} - 2 = \frac{20}{9} - 2 = 2\frac{2}{9} - 2 = \frac{2}{9}$ Ответ: $\frac{2}{9}$. 18. $\frac{35}{24} : \frac{15}{32} - 3 = \frac{35}{24} \cdot \frac{32}{15} - 3 = \frac{7 \cdot 4}{3 \cdot 3} - 3 = \frac{28}{9} - 3 = 3\frac{1}{9} - 3 = \frac{1}{9}$ Ответ: $\frac{1}{9}$. 19. $2 - \frac{15}{28} : \frac{10}{21} = 2 - \frac{15}{28} \cdot \frac{21}{10} = 2 - \frac{3 \cdot 3}{4 \cdot 2} = 2 - \frac{9}{8} = 2 - 1\frac{1}{8} = \frac{7}{8}$ Ответ: $0,875$ (или $\frac{7}{8}$).