12-4(x+2)=4x
x^5+x^4 = (x^3-x)(x^2+x+1)+x^2+x
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
x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少?
若x=π/3,|x+1|+|x+3|+...+|x+13|-|x+2|-|x+4|-...-|x+12|
解方程(6x+12)/(x^2+4x+4) + (x^2-4x+4)/(x^2-4) =(x^2-4)/(x^2-4x+
x*x+2x+x*x+10x+x*x+25+2x+x*x+1+1+16+x*x+4x*x+9-12x+16x*x+4-1
先化简,再求值:(x-2/x-x+2/x)/x-2/4x,x=2011
2x+3x+4x+5x+x+6x+7x=100
先化简再求值:(x+2-12/x-2)/(4-x)/(x-2),其中x=-1/2
5x+9x=6x*2+12 x+9-x/3=4
x=x/6+x/12+x/7+5+x/2+4=?