-3x^2-12+12x

x^3+x-30(分解因式);x^12-y^12;x^15+x^14+x^13.x^2+x+1 (x^21+x^15+x^12+x^9+x^6+x^3+1)/(x^2+x+1) (x-2)(x-3)+2(x-5)(x+6)-3(x^2-7x+12) 解方程：2x(x-1)-x(3x+2)=-x(x+2)-12 (x×x+3x+2)(x×x+7x+12)-24 1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550 化简：[√(x^2-6x+9)/x^2-x-12]*(x^3-16x)/(x^2-3x)-1/(x+3) {x＞3} 若x=π/3,｜x+1|+|x+3|+...+|x+13|-|x+2|-|x+4|-...-|x+12| x平方-6x+8分之2,x平方+x-6分之1,12+x-x平方分之3-x (（x²-5x+6)/(12-7x+x²))²÷((x²+3x+2)/(x
数学题[(x^2+x-12)/(2-x-x^2)]^2*[(x^2-3x+2)/(x^2+5x+4)]^2/[(x^2- 先化简,再求值:[(4x^2+12x)/(x^2+x-6)/[(x-2)/(x+2)-(x+2)/(x-2)]其中x-3