3x^3+12x-12x^2

通分:x+4/x^2-8x+15,x-5/x^2+x-12,x-3/x^2-x-20 4x+2x+x-3x=12 (x^5-12x^3+36x)/(x^2-6) 3x-{-4x+{5x-(12x-10]+2} 1+x+x^2+x^3+x^4+x^5+x^6+x^7+x^8+x^9+x^10+x^11+x^12=97.8x+x^2+x^3+x^4+x^5+x^6+x^7+x^8+x^9+x^10+x^11+x^12=97.8 好多年没有用过过数学公式了 想不起来怎么算了 想知道 X值是多少 计算：x^2-3x-1/x-1 - x^2+3x+3/x+3 + 2x+12/x+3 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) 解方程{3X+X+2X=12}3X+X+2X=12 (4/x-5)+(x-3)/(12-x)=(x-45)/(x^2-17x+60) (x*x+5x+2)(x*x+5x+3)-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必须用解方程 *-----------------------------------------------*| 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 || 数学题化简2(x-3)(x+3)-(x+3)(3-x)其中x=12(x-3)(x+3)-(x+3)(3-x) 其中x=1 数学化简3x-x^2/5x+4 x 18/4x-12(3x-x^2)/(5x+4) x 18/(4x-12) 3x·x-5x-122x·x·x-x·x-4x+3x·x·x-6x-5x·x+6x+64x·x+12x+7 化简：[√(x^2-6x+9)/x^2-x-12]*(x^3-16x)/(x^2-3x)-1/(x+3) {x＞3}