Ответ:

  1. а) \(0{,}51\cdot\frac23=\frac{51}{100}\cdot\frac23=\frac{17}{50}=0{,}34\).
  2. б) \(2{,}816:\frac47=2{,}816\cdot\frac74=4{,}928\).
  3. в) \(\frac37\cdot42{,}7=\frac{1281}{70}=18{,}3\).
  4. г) \(0{,}144:\frac{12}{13}=0{,}144\cdot\frac{13}{12}=0{,}156\).
  5. д) \(56{,}25\cdot\frac4{45}=1{,}25\cdot4=5\).
  6. е) \(\frac{21}{23}\cdot9{,}2=\frac{21}{23}\cdot\frac{46}{5}=\frac{42}{5}=8{,}4\).
  7. ж) \(6{,}3:2\frac14=6{,}3:\frac94=6{,}3\cdot\frac49=2{,}8\).
  8. з) \(6\frac47\cdot5{,}6=\frac{46}{7}\cdot\frac{28}{5}=36{,}8\).