(1+1/2+1/3+1/4+1/5)×(1/2+1/3+1/4+1/5+1/6)-(1+1/2+1/3+1/4+1/5+1/6)×(1/2+1/3+1/4+1/5)

来源:学生作业学帮网 编辑:学帮网 时间:2024/06/03 16:59:58

(1+1/2+1/3+1/4+1/5)×(1/2+1/3+1/4+1/5+1/6)-(1+1/2+1/3+1/4+1/5+1/6)×(1/2+1/3+1/4+1/5)

设1+1/2+1/3+1/4+1/5=a 1/2+1/3+1/4+1/5=b
(1+1/2+1/3+1/4+1/5)*(1/2+1/3+1/4+1/5+1/6)-(1+1/2+1/3+1/4+1/5+1/6)*(1/2+1/3+1/4+1/5)=a*(b+1/6)-(a+1/6)*b=1/6(a-b)=1/6