2x^2+3x+1=0 2x^2-7x-15=0 3x^2-7x-6=0

已知1+x+x^2+x^3=0,求x+x^2+x^3+x^4+x^5+x^6+x^7+x^8的值 已知1+x+x^2+x^3=0,求x+x^2+x^3+x^4+x^+x^6+x^7+x^8的值 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 (x+2)(x-3)(x-6)(x-1)=0 x^4+x^3+x^2+x+1=0,x^2006+x^2005+x^2004+x^2003+x^2002 方程（x+1)(x+2)(x+3)(x+4)(x+5)(x+6)(x+7)(x^2+8x+9)+64=0 x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? 1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550 已知 X=4- 根号3 求 (X*X*X*X-6X*X*X-2X*X+18X+23) / (X*X-8X+15)的值 2x+3x+4x+5x+x+6x+7x=100 解方程(3x^2+9x+7)/(x+1)-(2x^2+4x-3)/(x-1)-(x^3+x+1)/(x^2-1)=0 y=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)(x-10)的导数在x=1