17. Выполните умножение и деление: 5/12 · 4; 3/7 · 49; 5/8 : 25; 3/14 : 9; 5 : 15/19; 4 : 16/25; 5/11 : 5; 12/35 : 6; 10 : 3 1/3; 3 1/6 : 19/24; 3 3/7 · 1 1/6; 2 4/7 : 9/14; 5/49 · 4 1/12.

1. \(\frac{5}{12}\cdot4=\frac{20}{12}=\frac{5}{3}=1\frac{2}{3}\).
2. \(\frac{3}{7}\cdot49=3\cdot7=21\).
3. \(\frac{5}{8}:25=\frac{5}{8}\cdot\frac{1}{25}=\frac{1}{40}\).
4. \(\frac{3}{14}:9=\frac{3}{14}\cdot\frac{1}{9}=\frac{1}{42}\).
5. \(5:\frac{15}{19}=5\cdot\frac{19}{15}=\frac{19}{3}=6\frac{1}{3}\).
6. \(4:\frac{16}{25}=4\cdot\frac{25}{16}=\frac{25}{4}=6\frac{1}{4}\).
7. \(\frac{5}{11}:5=\frac{5}{11}\cdot\frac{1}{5}=\frac{1}{11}\).
8. \(\frac{12}{35}:6=\frac{12}{35}\cdot\frac{1}{6}=\frac{2}{35}\).
9. \(10:3\frac{1}{3}=10:\frac{10}{3}=10\cdot\frac{3}{10}=3\).
10. \(3\frac{1}{6}:\frac{19}{24}=\frac{19}{6}\cdot\frac{24}{19}=4\).
11. \(3\frac{3}{7}\cdot1\frac{1}{6}=\frac{24}{7}\cdot\frac{7}{6}=4\).
12. \(2\frac{4}{7}:\frac{9}{14}=\frac{18}{7}\cdot\frac{14}{9}=4\).
13. \(\frac{5}{49}\cdot4\frac{1}{12}=\frac{5}{49}\cdot\frac{49}{12}=\frac{5}{12}\).

Ответ: 1\(\frac{2}{3}\); 21; \(\frac{1}{40}\); \(\frac{1}{42}\); 6\(\frac{1}{3}\); 6\(\frac{1}{4}\); \(\frac{1}{11}\); \(\frac{2}{35}\); 3; 4; 4; 4; \(\frac{5}{12}\).