1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72=?

来源：学生作业帮助网编辑：作业帮时间：2024/11/18 05:37:56

1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72=?
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72=?

1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72=?
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72
=1-1/2+1/2-1/3+……+1/8-1/9
=1-1/9
=8/9

1-1/9=8/9

按一下计算器8/9

原式=1/1*2+1/2*3+1/3*4+……+1/8*9
=1-1/2+1/2-1/3+1/3-1/4+……+1/8-1/9
=1-1/9
=8/9