7.8乘3.4减15乘0.78加78乘0.81怎么算简便

7.8乘3.4减15乘0.78加78乘0.81怎么算简便
2024-11-29 23:55:41
推荐回答(3个)
回答(1):

7.8X3.4-15X0.78+78X0.81
=7.8X(3.4+1.5+8.1)
=7.8X13
=8X13-0.2X13
=104-2.6
=101.4

回答(2):

7.8*(3.4-1.5+8.1)=7.8*10=78

回答(3):

7.8×3.4-15×0.78+78×0.81
=78×0.34-0.15×78+78×0.81
=78×(0.34-0.15+0.81)
=78×1
=78