2/51+4/51+6/51+...50/51-1/51-3/51-...-49/51 2/51+4/51+6/51+...50/51-1/51-3/51-...-49/51 请高手指教,
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/23 01:27:43
![2/51+4/51+6/51+...50/51-1/51-3/51-...-49/51 2/51+4/51+6/51+...50/51-1/51-3/51-...-49/51 请高手指教,](/uploads/image/z/7104959-71-9.jpg?t=2%2F51%2B4%2F51%2B6%2F51%2B...50%2F51-1%2F51-3%2F51-...-49%2F51+2%2F51%2B4%2F51%2B6%2F51%2B...50%2F51-1%2F51-3%2F51-...-49%2F51+%E8%AF%B7%E9%AB%98%E6%89%8B%E6%8C%87%E6%95%99%2C)
2/51+4/51+6/51+...50/51-1/51-3/51-...-49/51 2/51+4/51+6/51+...50/51-1/51-3/51-...-49/51 请高手指教,
2/51+4/51+6/51+...50/51-1/51-3/51-...-49/51
2/51+4/51+6/51+...50/51-1/51-3/51-...-49/51 请高手指教,
2/51+4/51+6/51+...50/51-1/51-3/51-...-49/51 2/51+4/51+6/51+...50/51-1/51-3/51-...-49/51 请高手指教,
2/51+4/51+6/51+...50/51-1/51-3/51-...-49/51=(2/51-1/51)+(4/51-3/51)+……+(50/51-49/51)=25*1/51=25/51
2、4、6....50可以记作2n (n=1、2、3....25)
1、3、5....49可以记作2n-1(n=1、2、3....25)
份母相同:
原式=n*{[2n-(2n-1)]/51}=n*[(2n-2n+1)/51]=n*1/51=25/51
2/51+4/51+6/51+...50/51-1/51-3/51-...-49/51
=2/51-1/51+4/51-3/51+……+50/51-49/51
=1/51*25
=25/51