一道简算题~(0.1+0.12+0.123+0.1234)×(0.12+0.123+0.1234+0.12345)-(0.1+0.12+0.123+0.1234+0.12345)×(0.12+0.123+0.1234)

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/05 02:41:03

一道简算题~(0.1+0.12+0.123+0.1234)×(0.12+0.123+0.1234+0.12345)-(0.1+0.12+0.123+0.1234+0.12345)×(0.12+0.123+0.1234)
一道简算题~
(0.1+0.12+0.123+0.1234)×(0.12+0.123+0.1234+0.12345)-(0.1+0.12+0.123+0.1234+0.12345)×(0.12+0.123+0.1234)

一道简算题~(0.1+0.12+0.123+0.1234)×(0.12+0.123+0.1234+0.12345)-(0.1+0.12+0.123+0.1234+0.12345)×(0.12+0.123+0.1234)
(0.1+0.12+0.123+0.1234)×(0.12+0.123+0.1234+0.12345)-(0.1+0.12+0.123+0.1234+0.12345)×(0.12+0.123+0.1234)
设(0.12+0.123+0.123)为A
则 原式=(0.1+A)*(A+0.12345)-(A+0.1+0.12345)*A
=(A*A+A*0.12345+0.1*0.12345+0.1*A)-(A*A+A*0.1+A*0.12345)
=0.1*0.12345
=0.012345
原式=0.012345

为:
(0.1+0.12+0.123+0.1234)×(0.12+0.123+0.1234+0.12345)-(0.12+0.123+0.12340.12345)×(0.12+0.123+0.1234)+0.1×(0.12+0.123+0.1234)
等于0.1×(0.12+0.123+0.1234)