1/1x2+1/2x3=1/3x4+...+1/2005x2006+1/2006x2007=
1/1x2+1/2x3=1/3x4+...+1/2005x2006+1/2006x2007=
x+x2=-1 1+x+x2+x3+x4+……+x2005+x2006+x2007的值
已知:X5+X4+X3+X2+X+1=0,求X2008+X2007+X2006+.+X809=?
x6+x5+x4+x3+x2+x+1=0,求x2003+x2004+x2005+x2006+x2007+X2008=?
1/1x2+1/2x3+1/3x4...+1/2006x2007=等于多少啊!
1/1x2+1/2x3+1/3x4+1/4x5.1/2005x2006=?
1x2分之1+2x3分之1+3x4分之1+.+2006x2007分之1=
1/1x2+1/2X3+1/3X4+~+1/2005X2006
已知x2+x+!=0求1+x+x2+x3+x4.+x2006的值
1/1X2+1/2X3+1/3X4···+1/2006X2007(怎么做呀)
解方程组x1+x2=x2+x3=x3+x4=……=x2007+x2008=x2008+x2009=1,x1+x2+x3+
2006x2007+2007x2008+2008x2006-2/1+2+3+4+5'''''''+2006+2007