3x*9x*27x=9*9*9*9*9*9

x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? 如果3x*x-x=1那么9x*x*x*x+12x*x*x-3x*x-7x+2001等于多少 |X-1|+|X-2|+|X-3|+|X-4|+|X-5|+|X-6|+|X-7|+|X-8|+|X-9|+|X-10| x-3(20-x)=3x-7(9-x) 化简(x^2+3x+9)/(x^3-27)+(6x)/(9x-x^2)-(x-1)/(6+2x) 求化简：（x^2+3x+9)/(x^2-27)+(6x)/(9x-x^2)-(x-1)/(6+2x) x²+3x+9/(x²-27)+6x/(9x-x²)-(x-1)/(6+2x) 化简~(x²+3x+9/x²-27)+(6x/9x-x²)-(x-1/6+2x) 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), 解方程】(x+8)/(x-3)-(x-9)/(x-4)=(x+7)/(x+8)-(x+2)/(x+3) 解方程：（x-8）/(x-3)-(x-9)/(x-4)=(x+7)/(x+8)-(x+2)/(x+3)