2X²+7>9X

|X-1|+|X-2|+|X-3|+|X-4|+|X-5|+|X-6|+|X-7|+|X-8|+|X-9|+|X-10| x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? 2x^6×x³-3x^9+5x²×x^7等于多少 2-x/x²-9(1+2x-7/x²-4x+4)÷1/x+3 2x²-9x+7>0 (x+1)(x+2)(x+3)x+1=0则3x²+9x+7 解方程(x²-2)+2x²(x+3)-3x-(5x-7)=x(3x²-9x+17)+2 18/2X+9=54/7x为什么x=27及为什么x√x²+2x+1被化简为x|x+1|. x²+3x+9/(x²-27)+6x/(9x-x²)-(x-1)/(6+2x) (2x-6)/(x²-4x+4)÷(3-x)/(x²+6x+9)×(2-x)/(x+3) y=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)(x-10)的导数在x=1 设函数f(x)=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)(x-10),