1994+1/2-(1+1/3)+(2+1/2)-(3+1/3)+(4+1/2)-(5+1/3)+......+(1992+1/2)-(1999+1/3)
来源:百度知道 编辑:UC知道 时间:2024/06/08 10:37:35
1994+1/2-(1+1/3)+(2+1/2)-(3+1/3)+(4+1/2)-(5+1/3)+......+(1992+1/2)-(1999+1/3)
=1994+1/2-4/3+5/2-10/3+9/2-16/3+......+3985/2-5980/3
由1/2-4/3=-5/6
5/2-10/3=-5/6
...
3985/2-5980/3=-5/6(减数与被减数都加2,其差不变)
1994+1/2-4/3+5/2-10/3+9/2-16/3+......+3985/2-5980/3=1994+(1/2-4/3)+(5/2-10/3)+(9/2-16/3)+......+(3985/2-5980/3)=1994-5/6*[(3985-1)/4+1]=1994-5/6*997=-1163.167
1127又1/3
最后一项1999应该是1993吧??
答案是1994/2*(1+1/6)=1163+1/6
巧算1/1994+2/1994+3/1994+……+1993/1994=()
1/2+1/3+1/4+........+1/1994+1/1995+1/1996=????
:2*5/3 +5*8/3 +8*11/3 + ... 1991*1994/3 + 1994/1 =
1993+1992×1994/1993×1994-1
当x=(1+根号1994)/2时,求(4x^3-1997x-1994)^2001的值?
1994+1/2-4/3+5/2-10/3+9/2-16/3+.......+2985/2-5980/3
1994+1/2-4/3+5/2-10/3+9/2-16/3+.......+3985/2-5980/3
简便运算:1994+1/2-1又1/3+2又1/2-3又1/3+4又1/2-5又1/3+........+1992又1/2-1993又1/3
(1/2005-1)(1/2004-1)........(1/3-1)(1/2-1)
1+1/(1+2)+1/(1+2+3)+...+1/(1+2+3+...+100)