1) \(\frac{3}{4} : \frac{5}{7}\) 2) \(\frac{5}{18} : \frac{25}{27}\) 3) \(\frac{9}{16} : \frac{3}{64}\) 4) \(\frac{25}{72} : \frac{45}{63}\)

Решение:

1. \(\frac{3}{4} : \frac{5}{7} = \frac{3}{4} \times \frac{7}{5} = \frac{21}{20}\)
2. \(\frac{5}{18} : \frac{25}{27} = \frac{5}{18} \times \frac{27}{25} = \frac{1}{2} \times \frac{3}{5} = \frac{3}{10}\)
3. \(\frac{9}{16} : \frac{3}{64} = \frac{9}{16} \times \frac{64}{3} = 3 \times 4 = 12\)
4. \(\frac{25}{72} : \frac{45}{63} = \frac{25}{72} \times \frac{63}{45} = \frac{5}{8} \times \frac{7}{9} = \frac{35}{72}\)

Ответ: 1) \(\frac{21}{20}\); 2) \(\frac{3}{10}\); 3) 12; 4) \(\frac{35}{72}\).