简算 (1-1/2+1/3-1/4+1/5-1/6+...+1/49-1/50)/(1/26+1/27+...+1/50)

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/15 09:46:05
简算 (1-1/2+1/3-1/4+1/5-1/6+...+1/49-1/50)/(1/26+1/27+...+1/50)

简算 (1-1/2+1/3-1/4+1/5-1/6+...+1/49-1/50)/(1/26+1/27+...+1/50)
简算 (1-1/2+1/3-1/4+1/5-1/6+...+1/49-1/50)/(1/26+1/27+...+1/50)

简算 (1-1/2+1/3-1/4+1/5-1/6+...+1/49-1/50)/(1/26+1/27+...+1/50)
(1-1/2+1/3-1/4+1/5-1/6+...+1/49-1/50)/(1/26+1/27+...+1/50)
=[(1-1/2 )+(1/3+1/5+...+1/49)-(1/4+1/6+1/8+……1/50)]/(1/26+1/27+...+1/50)
=[1/2+(1/3+1/5+...+1/49)-1/2*(1/2+1/3+1/4+……1/25)]/(1/26+1/27+...+1/50)
=[(1/2-1/4)+(1/3+1/5+...+1/49)-1/2(1/3+1/4+……1/25)]/(1/26+1/27+...+1/50)
=[1/4+1/2*(1/3+1/5+...+1/25)+(1/27+1/29+……1/49)]/(1/26+1/27+...+1/50)