0.4X^2+5X-5=0

5/x^2+x - 1/x^2-x=0 (x^-2x)^-5(x^-2x)-6=0 如果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, 5(x的2次方+X-3)-4x(6+x)+x(-x+4)=0 已知实数x满足5x*x-3x-5=0,求代数式5x*x-2x-[1/5x*x-2x-5]的值. 已知实数x满足5x*x-3x-5=0,求代数式5x*x-2x-1/5x*x-2x-5的值. x-2 ,X>=0 f(x)=f[f(x+5)],x分段函数f(x)= x-2 ,X>=0 f[f(x+5)],x 若x^3+x^2+x+1=0,求代数式1+x+x^2+x^3+x^4+x^5+...+x^2006+x^2007的值 4x²+5x=81 x(x+5)=0 (2x-x)(x-1)=0 x(x+5)=5x-10 (3x-2)(x+1)=x(2x-1) x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? 判断函数f(x)=x^2-4x+5,x>0 -x^2-4x-5,x 数学f(x)=x(x+1)(x+2)(x+3)(x+4)(x+5),求f'(0)=? 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 已知f(x)=x(x-1)(x-2)(x-3)(x-4)(x-5),则f‘(0)为 *-----------------------------------------------*| 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 || x.x-5x+1=0,那么x.x+1/x.x 解方程x/(x-2)=2x/(x-3)+(1-x)/(x-5x+6) (x+12)(x-2)+(x+7)(x+8)-(x+5)(x-10),其中x=2