Запишем данные обыкновенные дроби:
1) \[\frac{1}{2}\]
2) \[\frac{6}{7}\]
3) \[\frac{4}{5}\]
4) \[\frac{1}{9}\]
5) \[\frac{3}{7}\]
6) \[\frac{9}{12} = \frac{3 \cdot 3}{3 \cdot 4} = \frac{3}{4}\]
7) \[\frac{8}{25}\]
8) \[\frac{6}{12} = \frac{6}{6 \cdot 2} = \frac{1}{2}\]
9) \[\frac{4}{9}\]
10) \[\frac{15}{60} = \frac{15}{15 \cdot 4} = \frac{1}{4}\]
11) \[\frac{13}{15}\]