a) \(\frac{7 \cdot 4}{14 \cdot 3} = \frac{7 \cdot 4}{7 \cdot 2 \cdot 3} = \frac{4}{2 \cdot 3} = \frac{2 \cdot 2}{2 \cdot 3} = \frac{2}{3}\)
б) \(\frac{2 \cdot 9}{9 \cdot 10} = \frac{2 \cdot 9}{9 \cdot 2 \cdot 5} = \frac{1}{5}\)
в) \(\frac{9 \cdot 7 \cdot 13}{7 \cdot 13 \cdot 18} = \frac{9 \cdot 7 \cdot 13}{7 \cdot 13 \cdot 9 \cdot 2} = \frac{1}{2}\)
Ответ: а) \(\frac{2}{3}\); б) \(\frac{1}{5}\); в) \(\frac{1}{2}\)