13. Вычислите: А) 2/3 : 5/7 Б) 1/4 : 1/2 В) 2/5 : 3/5 Г) 3/4 : 1/2 Д) 3/7 : 5/5 Е) 4/8 : 9/9 E) 1/2 : 3/5 3) 5/6 : 7/12 И) 4/9 : 2/5 К) 2/4 : 9/3 Л) 15/16 : 3/10 М) 7/12 : 21/16

13. Вычисления:

1. А) \( \frac{2}{3} : \frac{5}{7} = \frac{2}{3} \times \frac{7}{5} = \frac{14}{15} \)
2. Б) \( \frac{1}{4} : \frac{1}{2} = \frac{1}{4} \times \frac{2}{1} = \frac{2}{4} = \frac{1}{2} \)
3. В) \( \frac{2}{5} : \frac{3}{5} = \frac{2}{5} \times \frac{5}{3} = \frac{2}{3} \)
4. Г) \( \frac{3}{4} : \frac{1}{2} = \frac{3}{4} \times \frac{2}{1} = \frac{6}{4} = \frac{3}{2} = 1 \frac{1}{2} \)
5. Д) \( \frac{3}{7} : \frac{5}{5} = \frac{3}{7} : 1 = \frac{3}{7} \)
6. Е) \( \frac{4}{8} : \frac{9}{9} = \frac{1}{2} : 1 = \frac{1}{2} \)
7. Е) \( \frac{1}{2} : \frac{3}{5} = \frac{1}{2} \times \frac{5}{3} = \frac{5}{6} \)
8. 3) \( \frac{5}{6} : \frac{7}{12} = \frac{5}{6} \times \frac{12}{7} = \frac{60}{42} = \frac{10}{7} = 1 \frac{3}{7} \)
9. И) \( \frac{4}{9} : \frac{2}{5} = \frac{4}{9} \times \frac{5}{2} = \frac{20}{18} = \frac{10}{9} = 1 \frac{1}{9} \)
10. К) \( \frac{2}{4} : \frac{9}{3} = \frac{1}{2} : 3 = \frac{1}{2} \times \frac{1}{3} = \frac{1}{6} \)
11. Л) \( \frac{15}{16} : \frac{3}{10} = \frac{15}{16} \times \frac{10}{3} = \frac{150}{48} = \frac{25}{8} = 3 \frac{1}{8} \)
12. М) \( \frac{7}{12} : \frac{21}{16} = \frac{7}{12} \times \frac{16}{21} = \frac{112}{252} = \frac{8}{18} = \frac{4}{9} \)

Ответ: А) 14/15, Б) 1/2, В) 2/3, Г) 1 1/2, Д) 3/7, Е) 1/2, Е) 5/6, 3) 1 3/7, И) 1 1/9, К) 1/6, Л) 3 1/8, М) 4/9.