若1/2+1/6+1/12+.+1/x（x+1）=2013/2014,则x=?

来源：学生作业帮助网编辑：六六作业网时间：2024/05/09 05:34:31

若1/2+1/6+1/12+.+1/x（x+1）=2013/2014,则x=?若1/2+1/6+1/12+.+1/x（x+1）=2013/2014,则x=?若1/2+1/6+1/12+.+1/x（x+

若1/2+1/6+1/12+.+1/x（x+1）=2013/2014,则x=?
若1/2+1/6+1/12+.+1/x（x+1）=2013/2014,则x=?

若1/2+1/6+1/12+.+1/x（x+1）=2013/2014,则x=?
1/1×2+1/2×3+1/3×4+.+1/x（x+1）=2013/2014
1-1/2+1/2-1/3+1/3-1/4+……++1/x-1/（x+1）=2013/2014
1-1/(x+1)=2013/2014
1/(x+1)=1/2014
x+1=2014
x=2013

1/2+1/6+1/12+....+1/x（x+1）=2013/2014
1/1x2+1/2x3+1/3x4+……+1/x(x+1)=2013/2014
1-1/2+1/2-1/3+1/3-1/4+……+1/x-1/(x+1)=2013/2014
1-1/(x+1)=1-1/2014
x+1=2014
x=2013

由于1/[x(x+1)]=1/x-1/(x+1)
所以，1/2+1/6+1/12+...+1/x(x+1)
=(1-1/2)+(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+...+1/x-1/(x+1)
=1-1/(x+1)

既然1-1/(x+1)=2013/2014，那么,x=2013
完毕

*-----------------------------------------------*| 6 4 X | 8 X X | X X 5 || X X X | X X X | X 7 8 || X X X | X X X | X X X ||---------------+---------------+--------------- || X X X | X X X | 5 1 X || X X X | X 6 X | X X X || 8 X X | 3 5 X | 2 X X || 填九宫格帮帮忙.x x 6 x x 7 x x 98 x x x 3 x 1 x x 9 x x 6 x 5 x 3 x x x 3 x x x x 1 8x x x 9 x 1 x x x2 1 x x x x 6 x x x 6 x 7 x 3 x x 1 x x 9 x 2 x x x 47 x x 8 x x 5 x x (x^21+x^15+x^12+x^9+x^6+x^3+1)/(x^2+x+1) 1+x+x^2+x^3+x^4+x^5+x^6+x^7+x^8+x^9+x^10+x^11+x^12=97.8x+x^2+x^3+x^4+x^5+x^6+x^7+x^8+x^9+x^10+x^11+x^12=97.8 好多年没有用过过数学公式了想不起来怎么算了想知道 X值是多少约分：1、x*x-9/6-2x 2、x*x-1/x-x*x x/x-2+x-9/x-7=x+1/x-1+x-8/x-6, x/x-2+x-9/x-7=x+1/x-1+x-8/x-6, x^6-x^5+x^4-x^2+x-1 求一个数独答案X X X 9 X X X 8 2 X 6 3 X X 1 4 X 99 X 8 X X X X X XX X X 6 7 X 3 X XX 4 6 X 5 X 2 9 XX X 7 X 2 3 X X XX X X X X X 7 X 17 X 4 3 X X 6 2 X6 3 X X X 7 X X X 1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550必须用解方程若x*x+x+1+0,求x^7+2x^6+x^5+x^4+x^3+x*x+1的值化简：[√(x^2-6x+9)/x^2-x-12]*(x^3-16x)/(x^2-3x)-1/(x+3) {x＞3} 难倒爱因斯坦的九宫格X 7 X | X 8 1 | X X X |X X X | X 4 X | 7 5 9 |X X 5 | 7 X 9 | X 1 4 |5 X X | X X 8 | 3 9 X |3 9 6 | 4 X 7 | X X 2 |X 8 7 | 9 X X | X X X |4 X X | 6 X 5 | X X X | X X 4 | X X 1 |2 X X | X X X | X X X | X 3 X | X X X |X 6 3道简单的分式方程,1.3/(1-x^) = 2/(1+2x+x) - 5/1-2x+x^2.5x/(x^+x-6) + (2x-5)/(x^-x-12) = (7x-10)/(x^-6x+8)3.(x+1)/(x+2) + (x+6)/(x+7) = (x+2)/(x+3) + (x+5)/(x+6) 1/x(x+2)+1/(x+2)(x+4)+1/(x+4)(x+6)=3/2x+12 解下列方程!就三道!解下列方程.1、x/x-2 - 1-x²/x²-5x = 2x/x-3（x/x-2 - 1-x²不是一起的!）2、5x/x²+x-6 - 5-2x/x²-x-12=7x-10/x²-6x+8（5x/x²+x-6 - 5-2x不是一起的!）3、x-4/x-5 + x-8/x-9=x-7/x- 解方程式子 6-2x+3x=3x-4x+3x+18 6-x+3x=2x-5x+1 2x-1=5x-36-2x+3x=3x-4x+3x+18 6-x+3x=2x-5x+12x-1=5x-3 如下9*9宫图如何填x x x 1 x x x 2 9x x 5 x x x x x 4x 6 8 x x x x x xx x x 7 x x 5 x xx 2 x x 6 x x 8 xx x 3 x x 9 x x xx x x x 5 x 1 6 x 4 x x x 3 x x x x 7 x x x x 2 x x x