④) 1) 3/5 · 1⁵/₆ = ? 2) 3/8 · 16 = ? 3) 2⅚ · 3 = ? 4) 1¼ · 2⅘ = ?

Решение:

1. 1) \( \frac{3}{5} \cdot 1\frac{5}{6} = \frac{3}{5} \cdot \frac{11}{6} = \frac{1}{5} \cdot \frac{11}{2} = \frac{11}{10} = 1\frac{1}{10} \)
2. 2) \( \frac{3}{8} \cdot 16 = \frac{3}{8} \cdot \frac{16}{1} = 3 \cdot 2 = 6 \)
3. 3) \( 2\frac{5}{6} \cdot 3 = \frac{17}{6} \cdot 3 = \frac{17}{2} = 8\frac{1}{2} \)
4. 4) \( 1\frac{1}{4} \cdot 2\frac{4}{5} = \frac{5}{4} \cdot \frac{14}{5} = \frac{1}{4} \cdot 14 = \frac{14}{4} = \frac{7}{2} = 3\frac{1}{2} \)

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