50. \(\frac{13}{14} : \frac{7}{26} \times \frac{3}{8}\)

Решение:

\(\frac{13}{14} \div \frac{7}{26} \times \frac{3}{8} = \frac{13}{14} \times \frac{26}{7} \times \frac{3}{8} = \frac{13 \times 26 \times 3}{14 \times 7 \times 8} = \frac{13 \times 13 \times 3}{7 \times 7 \times 4} = \frac{507}{196}\)

Ответ: \(\frac{507}{196}\)