Ответ:

  1. \(9\%=\frac{9}{100}=0{,}09\);
  2. \(143\%=\frac{143}{100}=1{,}43\);
  3. \(680\%=\frac{680}{100}=\frac{34}{5}=6{,}8\).

Ответ: 9% = \(\frac{9}{100}=0{,}09\); 143% = \(\frac{143}{100}=1{,}43\); 680% = \(\frac{34}{5}=6{,}8\).