Вопрос:

Вычислите: а) \(\frac{8}{15}\cdot\frac{2}{120}:\frac{40}{30}\); б) \(\frac{13}{50}\cdot\frac{26}{12}\cdot\frac{52}{13}\); в) \(\frac{42}{60}\cdot\frac{12}{7}\cdot\frac{3}{21}\).

Ответ:

а)

\[\frac{8}{15}\cdot\frac{2}{120}:\frac{40}{30}=\frac{8}{15}\cdot\frac{1}{60}\cdot\frac{30}{40}=\frac{1}{150}\]

б)

\[\frac{13}{50}\cdot\frac{26}{12}\cdot\frac{52}{13}=\frac{13}{50}\cdot\frac{13}{6}\cdot4=\frac{169}{75}\]

в)

\[\frac{42}{60}\cdot\frac{12}{7}\cdot\frac{3}{21}=\frac{7}{10}\cdot\frac{12}{7}\cdot\frac{1}{7}=\frac{6}{35}\]

Ответ: а) \(\frac{1}{150}\); б) \(\frac{169}{75}\); в) \(\frac{6}{35}\).