339. Найдите произведение: 1) 0,4 * 5/9; 2) 8/27 * 0,75; 3) 1,5 * 1/6; 4) 2 1/7 * 2,8

1) \(0,4 \cdot \frac{5}{9} = \frac{4}{10} \cdot \frac{5}{9} = \frac{2}{5} \cdot \frac{5}{9} = \frac{2 \cdot 5}{5 \cdot 9} = \frac{2 \cdot 1}{1 \cdot 9} = \frac{2}{9}\) 2) \(\frac{8}{27} \cdot 0,75 = \frac{8}{27} \cdot \frac{75}{100} = \frac{8}{27} \cdot \frac{3}{4} = \frac{8 \cdot 3}{27 \cdot 4} = \frac{2 \cdot 1}{9 \cdot 1} = \frac{2}{9}\) 3) \(1,5 \cdot \frac{1}{6} = \frac{15}{10} \cdot \frac{1}{6} = \frac{3}{2} \cdot \frac{1}{6} = \frac{3 \cdot 1}{2 \cdot 6} = \frac{1 \cdot 1}{2 \cdot 2} = \frac{1}{4}\) 4) \(2 \frac{1}{7} \cdot 2,8 = \frac{15}{7} \cdot \frac{28}{10} = \frac{15 \cdot 28}{7 \cdot 10} = \frac{3 \cdot 4}{1 \cdot 2} = \frac{12}{2} = 6\) Ответ: 1) 2/9 2) 2/9 3) 1/4 4) 6