1-1/2+1/6+1/12+1/20+1/30+...+1/72+1/901+1/2-5/6+7/12-9/20+11/30-13/42+15/56
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/21 07:11:45
![1-1/2+1/6+1/12+1/20+1/30+...+1/72+1/901+1/2-5/6+7/12-9/20+11/30-13/42+15/56](/uploads/image/z/4001995-19-5.jpg?t=1-1%EF%BC%8F2%2B1%EF%BC%8F6%2B1%EF%BC%8F12%2B1%EF%BC%8F20%2B1%EF%BC%8F30%2B...%2B1%EF%BC%8F72%2B1%EF%BC%8F901%2B1%EF%BC%8F2-5%EF%BC%8F6%2B7%EF%BC%8F12-9%EF%BC%8F20%2B11%EF%BC%8F30-13%EF%BC%8F42%2B15%EF%BC%8F56)
1-1/2+1/6+1/12+1/20+1/30+...+1/72+1/901+1/2-5/6+7/12-9/20+11/30-13/42+15/56
1-1/2+1/6+1/12+1/20+1/30+...+1/72+1/90
1+1/2-5/6+7/12-9/20+11/30-13/42+15/56
1-1/2+1/6+1/12+1/20+1/30+...+1/72+1/901+1/2-5/6+7/12-9/20+11/30-13/42+15/56
1-1/2+1/6+1/12+1/20+1/30+...+1/72+1/90
=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+...+1/8-1/9+1/9-1/10
=1-1/10
=9/10
1+1/2-5/6+7/12-9/20+11/30-13/42+15/56
=1+1/2-1/2-1/3+1/3+1/4-1/4-1/5+1/5+1/6-1/6-1/7+1/7+1/8
=1+1/8
=9/8