第1个回答 2021-09-17
1.21ⅹ1.8-8.2ⅹO.21怎么简便计算?
=(1+0.21)×1.8-8.2×0.21
=1×1.8+0.21×1.8-8.2×0.21
=1.8-0.21×(8.2-1.8)
=1.8-0.21×6.4
=1.8-0.21×(6+0.4)
=1.8-0.21×6-0.21×0.4
=1.8-1.26-0.084
=0.456
第2个回答 2021-09-17
确定自己没写错题目吧
这道题没有简便计算方法
如果中间是加号的话,是可以简便计算的
1.21×1.8+8.2×0.21
=(1+0.21)×1.8+8.2×0.21
=1×1.8+0.21×1.8+8.2×0.21
=1.8+0.21×10
=1.8+2.1
=3.9
第3个回答 2021-09-16
我来给你算一下,1.21*1.8-8.2*0.21=1.21*(2-0.2)-8.2*(0.2+0.01)=2.42-0.242-1.64-0.082=2.42-1.64-(0.242+0.082)=0.78-0.324=0.456,很简单的,希望对你有帮助,供参考!
第4个回答 2021-09-17
原式=(1+0.21)*1.8—8.2*0.21
=1.8+1.8*0.21—8.2*0.21
=1.8+(1.8—8.2)*0.21
=1.8—6.4*0.21
=1.8—6*0.21—0.4*0.21
=1.8—1.21—0.84
=0.59—0.84
=—0.25