15.37*7.89-9.37*7.89+2.11-9.37*2.11 这题怎么简便呀

问题描述:

15.37*7.89-9.37*7.89+2.11-9.37*2.11 这题怎么简便呀

7.89(15.37-9.37)+2.11(1-9.37)=7.89*6-2.11*(-8.37)=47.34+17.66=65