54/7: 1 5/21-(5 2/15 • 3/22 + 1 14/15)=

1)5 4/7÷1 5/21=(39×21)/(7×26)=1 1/2. 2)5 2/15×3/22=(77×3)/(15×22)=7/10. 3)7/10+1 14/15=7/10+29/15=2 19/30. 4)1 1/2-2 19/30=(45-79)/30=-34/30=-17/15=-1 2/15