5.459 Найдите произведение: a) \(\frac{4}{7}\) · 14; б) 2 · \(\frac{5}{8}\); в) 10 · \(\frac{3}{8}\); г) \(\frac{3}{7}\) · 21; д) \(\frac{9}{17}\) · 0; ж) \(\frac{1}{3}\) · 24; e) \(\frac{11}{100}\) · 1; з) \(\frac{1}{31}\) · 31.

a) \(\frac{4}{7}\) · 14 = \(\frac{4 \cdot 14}{7}\) = \(\frac{4 \cdot 2 \cdot 7}{7}\) = 4 · 2 = 8

Ответ: 8

б) 2 · \(\frac{5}{8}\) = \(\frac{2 \cdot 5}{8}\) = \(\frac{10}{8}\) = \(\frac{5}{4}\) = 1\(\frac{1}{4}\)

Ответ: 1\(\frac{1}{4}\)

в) 10 · \(\frac{3}{8}\) = \(\frac{10 \cdot 3}{8}\) = \(\frac{30}{8}\) = \(\frac{15}{4}\) = 3\(\frac{3}{4}\)

Ответ: 3\(\frac{3}{4}\)

г) \(\frac{3}{7}\) · 21 = \(\frac{3 \cdot 21}{7}\) = \(\frac{3 \cdot 3 \cdot 7}{7}\) = 3 · 3 = 9

Ответ: 9

д) \(\frac{9}{17}\) · 0 = 0

Ответ: 0

ж) \(\frac{1}{3}\) · 24 = \(\frac{1 \cdot 24}{3}\) = \(\frac{24}{3}\) = 8

Ответ: 8

e) \(\frac{11}{100}\) · 1 = \(\frac{11}{100}\)

Ответ: \(\frac{11}{100}\)

з) \(\frac{1}{31}\) · 31 = \(\frac{1 \cdot 31}{31}\) = 1

Ответ: 1