找规律计算1.2.3.4

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/03 06:22:01
找规律计算1.2.3.4

找规律计算1.2.3.4
找规律计算1.2.3.4

找规律计算1.2.3.4
1、2[(1/1-1/2)+(1/2-1/3)+、、、+(1/99-1/100)]
=2(1-1/100)=99/50
2、[1/3+(1/3-1/5)/2+(1/5-1/7)/2+(1/21-1/23)/2]
=1/3+(1/3-1/23)/2
=1/2-1/23=21/46
3、1/3+1/4-1/4-1/5-1/5-1/6-1/6-1/7-1/7-1/8-1/8-1/9
=1/3-2/5-1/3-2/7-1/4-1/9
=-24/35-13/36
=-1319/1260
4、3/2×5/4×7/6×9/8×11/10×2/3×4/5×6/7×8/9
=11/10