1+1/1x2+1/2x3+1/3x4+...+1/2007x2008=?

1/1x2+1/2x3+1/3x4+1/4x5+.+1/2007x2008=多少 怎么计算 解方程组x1+x2=x2+x3=x3+x4=……=x2007+x2008=x2008+x2009=1,x1+x2+x3+ 1/1X2+1/2X3+1/3X4+1/4X5+1/5X6……1/2007X2008 2/1X2+2/2X3+2/3X4+……+2/2007X2008等于多少（需要过程）急! 已知：X5+X4+X3+X2+X+1=0,求X2008+X2007+X2006+.+X809=? 急求高手解答1/1x2+1/2x3+1/3x4+1/4x5+.+1/2007x2008+1/2008x2009帮忙列出每 x6+x5+x4+x3+x2+x+1=0,求x2003+x2004+x2005+x2006+x2007+X2008=? 设x1,x2,…,x2008都是+1或-1,求证：x1+2x2+3x3+…2008x2008≠0 求线性方程组 x2-x3-x4=0 x1+x2-x3+3x4=1 x1-x2+x3+5x4=-1 x1+2x2-2x3+ X1+2X2-X3+X4=1 1/1x2=1-1/2,1/2x3=1/2-1/3,1/3x4=1/3-1/4,则1/2007x2008=(),并且用含 求齐次线性方程组x1+2x2+x3+x4+x5=1 2x1+4x2+3x3+x4+x5=2 -x1-2x2+x3+3x4