2005x^2-(2005^2-1)x-2005用换元法解

化简:1+x+x(1+x)+x(1+x)^2+x(1+x)^3+……+x(1+x)^2005 x^4+x^3+x^2+x+1=0,x^2006+x^2005+x^2004+x^2003+x^2002 1/x(x+1)+1/(x+1)(x+2)+1/(x+2)(x+3)+.+1/(x+2004)(x+2005) 当x=1时,x^2006-x^2005+x^2004-x^2003+x^2002-……+x^2-x 1/(x+1)(x+2)+1/(x+2)(x+3)+(x+3)(x+4)+.+1/(x+2005)(x+2006)=1/2x+4012 求X 已知x^2+x+1=0,求1+x+x^2+x^3+x^4+.+x^2005的值. 化简求值:1/x(x+1)+1/(x+)(x+2)+.1/(x+2005)(x+2006),其中X=1. 若x^3+x^2+x+1=0,求x^2008+x^2007+x^2006+x^2005的值 求导：Y=(x-1)(x-2)(x-3)…(x-2005) (x＞2005) 1/(x+1)(x+2)+1/(x+2)(x+3)+1/(x+3)(x+4)+...1/(x+2005)(x+2006)=1/2x+4024 1/（x+1)(x+2） + 1/(x+2)(x+3) + 1/(x+3)(x+4) + ...+ 1/(x+2005)(x+2006) = 1/2x+4012 1/(x+1)(x+2) + 1/(x+2)(x+3) + 1/(x+3)(x+4) + ...+1/ (x+2005)(x+2006) = 1/2x + 4012 1/(x+1)(x+2) + 1/(x+2)(x+3) + 1/(x+3)(x+4) …… 1/(x+2005)(x+2006)=1/2x+4012 1+x+x^2+...+x^2004+x^2005=0 求x^2006 已知1+x+x^2+.+x^2004+x^2005=0,则x^2006=_____ 求|x-1|+|x-2|+|x-3|+.+|x-2004|+|x-2005|最小值 *-----------------------------------------------*| 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