а) \(1 \frac{4}{9} \cdot 9 = 1 \cdot 9 + \frac{4}{9} \cdot 9 = 9 + 4 = 13\).\nб) \((\frac{5}{14} + \frac{1}{7}) \cdot 7 = (\frac{5}{14} + \frac{2}{14}) \cdot 7 = \frac{7}{14} \cdot 7 = \frac{1}{2} \cdot 7 = 3.5\).\nв) \(4 \cdot \frac{3}{5} - \frac{4}{9} + \frac{4}{9} \cdot 4 - \frac{2}{5} = \frac{12}{5} - \frac{4}{9} + \frac{16}{9} - \frac{2}{5} = \frac{10}{5} + \frac{12}{9} = 2 + 1.333 = 3.333\).