13. Вычислите: A) 2/3 : 5/7 Б) 1/4 : 1/2 B) 2/5 : 2/3 Д) 3/7 : 5/5 E) 4/8 : 9/9 E) 1/2 : 3/5 Ж) 2/4 : 3/5 3) 5/6 : 7/12 И) 4/9 : 2/5 K) 2/9 : 4/3 Л) 15/16 : 3/10 M) 7/12 : 21/16

13. Вычислите:

1. A) \( \frac{2}{3} : \frac{5}{7} = \frac{2}{3} \times \frac{7}{5} = \frac{14}{15} \)
2. Б) \( \frac{1}{4} : \frac{1}{2} = \frac{1}{4} \times \frac{2}{1} = \frac{2}{4} = \frac{1}{2} \)
3. B) \( \frac{2}{5} : \frac{2}{3} = \frac{2}{5} \times \frac{3}{2} = \frac{3}{5} \)
4. Д) \( \frac{3}{7} : \frac{5}{5} = \frac{3}{7} : 1 = \frac{3}{7} \)
5. E) \( \frac{4}{8} : \frac{9}{9} = \frac{1}{2} : 1 = \frac{1}{2} \)
6. E) \( \frac{1}{2} : \frac{3}{5} = \frac{1}{2} \times \frac{5}{3} = \frac{5}{6} \)
7. Ж) \( \frac{2}{4} : \frac{3}{5} = \frac{1}{2} \times \frac{5}{3} = \frac{5}{6} \)
8. 3) \( \frac{5}{6} : \frac{7}{12} = \frac{5}{6} \times \frac{12}{7} = \frac{5 \times 2}{7} = \frac{10}{7} = 1 \frac{3}{7} \)
9. И) \( \frac{4}{9} : \frac{2}{5} = \frac{4}{9} \times \frac{5}{2} = \frac{2 \times 5}{9} = \frac{10}{9} = 1 \frac{1}{9} \)
10. K) \( \frac{2}{9} : \frac{4}{3} = \frac{2}{9} \times \frac{3}{4} = \frac{1 \times 1}{3 \times 2} = \frac{1}{6} \)
11. Л) \( \frac{15}{16} : \frac{3}{10} = \frac{15}{16} \times \frac{10}{3} = \frac{5 \times 5}{8 \times 1} = \frac{25}{8} = 3 \frac{1}{8} \)
12. M) \( \frac{7}{12} : \frac{21}{16} = \frac{7}{12} \times \frac{16}{21} = \frac{1 \times 4}{3 \times 3} = \frac{4}{9} \)

Ответ: А) 14/15; Б) 1/2; В) 3/5; Д) 3/7; Е) 1/2; Е) 5/6; Ж) 5/6; 3) 1 3/7; И) 1 1/9; K) 1/6; Л) 3 1/8; M) 4/9.