3. Вычислите: a) \(2\frac{2}{13} + \frac{5}{13}\); б) \(4\frac{4}{5} - 3\frac{1}{4}\); в) \(\frac{4}{7} : \frac{2}{15}\).

3. Вычисление:

1. а) \(2\frac{2}{13} + \frac{5}{13} = 2 + \frac{2+5}{13} = 2\frac{7}{13}\)
2. б) \(4\frac{4}{5} - 3\frac{1}{4} = \frac{24}{5} - \frac{16}{4} = \frac{96}{20} - \frac{80}{20} = \frac{16}{20} = \frac{4}{5}\)
3. в) \(\frac{4}{7} : \frac{2}{15} = \frac{4}{7} \cdot \frac{15}{2} = \frac{4 \cdot 15}{7 \cdot 2} = \frac{2 \cdot 15}{7 \cdot 1} = \frac{30}{7} = 4\frac{2}{7}\)

Ответ: а) \(2\frac{7}{13}\); б) \(\frac{4}{5}\); в) \(4\frac{2}{7}\).