5) \(4\frac{4}{14}+15\frac{6}{21}\)

Сократим дроби:

\(\frac{4}{14}=\frac{2}{7}\), \(\frac{6}{21}=\frac{2}{7}\).

\(4\frac{4}{14}+15\frac{6}{21}=19+\frac{2}{7}+\frac{2}{7}=19\frac{4}{7}\).

Ответ: \(19\frac{4}{7}\).