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