a) \(\frac{7 \cdot 4}{14 \cdot 3} = \frac{7 \cdot 4}{7 \cdot 2 \cdot 3} = \frac{4}{2 \cdot 3} = \frac{2 \cdot 2}{2 \cdot 3} = \frac{2}{3}\)
Ответ: \(\frac{2}{3}\)