1. Вычислить: 1. 15⋅5/19 2. 36/56⋅7/18 3. 18/64⋅8/18

Ответ: 1) 75/19; 2) 9/28; 3) 1/8

Решение:

1. 15 \(\cdot\) \(\frac{5}{19}\) = \(\frac{15}{1}\) \(\cdot\) \(\frac{5}{19}\) = \(\frac{15 \cdot 5}{1 \cdot 19}\) = \(\frac{75}{19}\)

2. \(\frac{36}{56}\) \(\cdot\) \(\frac{7}{18}\) = \(\frac{36 \cdot 7}{56 \cdot 18}\) = \(\frac{2 \cdot 1}{8 \cdot 1}\) = \(\frac{2}{8}\) = \(\frac{1}{4}\)

3. \(\frac{18}{64}\) \(\cdot\) \(\frac{8}{18}\) = \(\frac{18 \cdot 8}{64 \cdot 18}\) = \(\frac{1 \cdot 1}{8 \cdot 1}\) = \(\frac{1}{8}\)

Ответ: 1) 75/19; 2) 9/28; 3) 1/8