Ответ:

  1. \(\frac{12}{20}=\frac{12:4}{20:4}=\frac{3}{5}\).
  2. \(\frac{18}{24}=\frac{18:6}{24:6}=\frac{3}{4}\).
  3. \(0{,}55=\frac{55}{100}=\frac{55:5}{100:5}=\frac{11}{20}\).
  4. \(0{,}82=\frac{82}{100}=\frac{82:2}{100:2}=\frac{41}{50}\).