100+99.9-99.8-99.7+99.6+99.5-99.4-99.3+…...+0.4+0.3-0.2-0.1

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/29 23:28:52
100+99.9-99.8-99.7+99.6+99.5-99.4-99.3+…...+0.4+0.3-0.2-0.1

100+99.9-99.8-99.7+99.6+99.5-99.4-99.3+…...+0.4+0.3-0.2-0.1
100+99.9-99.8-99.7+99.6+99.5-99.4-99.3+…...+0.4+0.3-0.2-0.1

100+99.9-99.8-99.7+99.6+99.5-99.4-99.3+…...+0.4+0.3-0.2-0.1
(100-99.8)+(99.9-99.7)+(99.6-99.4)+.+(0.3-0.1)
=0.2*250
=50

98

从99.9到-0.1一共有1000项
注意每四项的和加起来都为0
所以:100+99.9-99.8-99.7+99.6+99.5-99.4-99.3+…...+0.4-0.3-0.2+0.1=100
但是:你所给的题目有错误,+0.3是否为-0.3,-0.1为+0.1,否则没有办法找到规律进行计算

100+99.9-99.8-99.7+99.6+99.5-99.4-99.3+…...+0.4+0.3-0.2-0.1
=100+0.1-0.1+0.1-0.1+………+0.1-0.1
=100