№1. Выполни умножение дробей:

Решение:

1. \( \frac{1}{2} \cdot \frac{1}{3} = \frac{1 \cdot 1}{2 \cdot 3} = \frac{1}{6} \)
2. \( \frac{2}{5} \cdot \frac{3}{4} = \frac{2 \cdot 3}{5 \cdot 4} = \frac{6}{20} = \frac{3}{10} \)
3. \( \frac{5}{7} \cdot 2 = \frac{5}{7} \cdot \frac{2}{1} = \frac{5 \cdot 2}{7 \cdot 1} = \frac{10}{7} = 1\frac{3}{7} \)
4. \( \frac{7}{10} \cdot \frac{3}{4} = \frac{7 \cdot 3}{10 \cdot 4} = \frac{21}{40} \)
5. \( \frac{1}{4} \cdot \frac{2}{3} = \frac{1 \cdot 2}{4 \cdot 3} = \frac{2}{12} = \frac{1}{6} \)
6. \( \frac{2}{3} \cdot \frac{3}{8} = \frac{2 \cdot 3}{3 \cdot 8} = \frac{6}{24} = \frac{1}{4} \)
7. \( \frac{15}{16} \cdot \frac{8}{25} = \frac{15 \cdot 8}{16 \cdot 25} = \frac{3 \cdot 5 \cdot 8}{2 \cdot 8 \cdot 5 \cdot 5} = \frac{3}{10} \)
8. \( \frac{3}{4} \cdot \frac{1}{6} = \frac{3 \cdot 1}{4 \cdot 6} = \frac{3}{24} = \frac{1}{8} \)

Ответ: 1) \(\frac{1}{6}\); 2) \(\frac{3}{10}\); 3) \(1\frac{3}{7}\); 4) \(\frac{21}{40}\); 5) \(\frac{1}{6}\); 6) \(\frac{1}{4}\); 7) \(\frac{3}{10}\); 8) \(\frac{1}{8}\).