③) 2) 1⅖ · ¼ = ? 3) 0.4 · ⅖ = ? 4) 7/25 · 2 = ?

Решение:

1. 1) \( 1\frac{2}{5} \cdot \frac{1}{4} = \frac{7}{5} \cdot \frac{1}{4} = \frac{7}{20} \)
2. 2) \( 0.4 \cdot \frac{2}{5} = \frac{4}{10} \cdot \frac{2}{5} = \frac{2}{5} \cdot \frac{2}{5} = \frac{4}{25} \)
3. 3) \( \frac{7}{25} \cdot 2 = \frac{7}{25} \cdot \frac{2}{1} = \frac{14}{25} \)

Ответ: 1) \(\frac{7}{20}\); 2) \(\frac{4}{25}\); 3) \(\frac{14}{25}\).