1. Сократите: \(\frac{9}{15}\), \(\frac{8}{56}\), \(\frac{42}{90}\), \(\frac{38\cdot18}{9\cdot19}\).

\(\frac{9}{15}=\frac{3}{5}\); \(\frac{8}{56}=\frac{1}{7}\); \(\frac{42}{90}=\frac{7}{15}\); \(\frac{38\cdot18}{9\cdot19}=\frac{2\cdot18}{9}=4\).

Ответ: \(\frac{3}{5};\ \frac{1}{7};\ \frac{7}{15};\ 4\).