1. Сократите: 28/42, 45/60, 72/96.

1. \(\frac{28}{42}=\frac{28\div14}{42\div14}=\frac{2}{3}\).

2. \(\frac{45}{60}=\frac{45\div15}{60\div15}=\frac{3}{4}\).

3. \(\frac{72}{96}=\frac{72\div24}{96\div24}=\frac{3}{4}\).

Ответ: \(\frac{2}{3},\ \frac{3}{4},\ \frac{3}{4}\).