2x^2-7x+2=0 求x+1/x

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 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, 已知x*x+x-1=0 求x*x*x-2x+11=? 已知x*x+x-1=0求x*x*x-2x+2010的值 一个“整式的乘法”的问题请先阅读下列解题过程,再仿做下面的问题.已知X*X + X - 1=0,求X*X*X + 2*X*X + 3的值.解X*X*X + 2X*X +3=X*X*X +X*X -X +X*X +X +3=X{X*X +X -1} +X*X +X -1 +4=0+0+4=4+ x + X*X + X*X*X=0.+ X*X + X*X*X X^2-3X-2=0,求( x - 2x-1/x )÷(x-1)/(x^2-2x) f(x)=(x^2-2x-1)/x (x>0)求f(x)最小值 （x）-2x·x-x-2x+1=0求x的值, 已知x*x-3x+1=0求√(x*x+1/x-2)=? f(x)+f((x-1)/x)=2x; x!=0,1; 求f(x) f(x)+f[(x-1)/x]=2x x不等于0,1.求f(x). 已知x^-x-1=0,求x^4+x^3-x^2-4x+3 (x-1)(x-2)(x-3)(x-4)=(x+5)(x+6)(x+7)求X等于几? 已知x=2π+1求 |x-1|+|x-2|+|x-3|+|x-4|+|x-5|+|x-6|+|x-7|+|x-8|+|x-9|+|x-10| 已知x=2π+1.求(X-1)+(X-2)+(X-3)+(X-4)+(X-5)+(X-6)+(X-7)+(X-8)+(X-9)+(X-10) 1/(x^2+7x)-1/(x^2+7x)+1/(x^2+7X+18)-1/(x^2+7X+12)=0求X 求一个数独答案X X X 9 X X X 8 2 X 6 3 X X 1 4 X 99 X 8 X X X X X XX X X 6 7 X 3 X XX 4 6 X 5 X 2 9 XX X 7 X 2 3 X X XX X X X X X 7 X 17 X 4 3 X X 6 2 X6 3 X X X 7 X X X *-----------------------------------------------*| 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 ||