9 8 x 5 3 怎 么 巧 算

|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? 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+3)/(x+2)-(x+5)/(x+4)=(x+7)/(x+6)-(x+9)/(x+8) 解分式方程 x-7/x-9+x-3/x-5=x-4/x-6+x-6/x-8 （1） x-3/x-2 - x-5/x-4=x-7/x-6 - x-9/x-8 因式分解：x^9+x^8-x^6-x^5+x^3+x^2-1 1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550 x^2+2x-7 x^2+6x+8 x^2-3x+5 3x^2-6x+9 2x^2-4x+5 3 1x()+2x()+3x()+4x()+5x()+6x()+7x()+8x()加9x()+10x()=1980 (x+1)(x+2)(x+3)(x+4)(x+5)(x+6)(x+7)(x+8)(x+9)(x+10)请化简