10分之7*84+2又5分之3*0.7-70%(简算,急~~~~~~~~~~~~~~)

问题描述:

10分之7*84+2又5分之3*0.7-70%(简算,急~~~~~~~~~~~~~~)

应该是10分之7*8.4+2又5分之3*0.7-70%
=0.7*8.4+2.6*0.7-0.7
=0.7*(8.4+2.6-1)
=0.7*10
=7