Ответ:\(\frac{20}{25}=\frac{20:5}{25:5}=\frac45\).\(\frac{36}{72}=\frac{36:36}{72:36}=\frac12\).\(\frac{105}{30}=\frac{105:15}{30:15}=\frac72\).Ответ: \(\frac45,\ \frac12,\ \frac72\).