60. Найдите произведение:

Решение:

1. \( 4 \cdot \frac{4}{21} = \frac{4}{1} \cdot \frac{4}{21} = \frac{16}{21} \)
2. \( 6 \frac{7}{18} = \frac{115}{18} \)
3. \( \frac{5}{14} \cdot 28 = \frac{5}{14} \cdot \frac{28}{1} = \frac{5 \cdot 28}{14} = 5 \cdot 2 = 10 \)
4. \( \frac{5}{5} \cdot \frac{3}{7} = 1 \cdot \frac{3}{7} = \frac{3}{7} \)
5. \( 2 \frac{2}{15} \cdot 1 \frac{9}{16} = \frac{32}{15} \cdot \frac{25}{16} = \frac{32 \cdot 25}{15 \cdot 16} = \frac{(16 \cdot 2) \cdot (5 \cdot 5)}{(3 \cdot 5) \cdot 16} = \frac{2 \cdot 5}{3} = \frac{10}{3} = 3 \frac{1}{3} \)
6. \( 1 \frac{7}{8} \cdot 1 \frac{1}{15} \cdot 7 \frac{7}{16} = \frac{15}{8} \cdot \frac{16}{15} \cdot \frac{119}{16} = \frac{15 \cdot 16 \cdot 119}{8 \cdot 15 \cdot 16} = \frac{119}{8} = 14 \frac{7}{8} \)