№5. Сократите: 9/15, 8/56, 42/90.

1. \(\frac{9}{15}=\frac{9\div3}{15\div3}=\frac35\).
2. \(\frac{8}{56}=\frac{8\div8}{56\div8}=\frac17\).
3. \(\frac{42}{90}=\frac{42\div6}{90\div6}=\frac7{15}\).

Ответ: \(\frac35;\ \frac17;\ \frac7{15}\).