(x-8)(x-5)=x*x-415

x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? (x+12)(x-2)+(x+7)(x+8)-(x+5)(x-10),其中x=2 x-4/x-5 - x-5/x-6=x-7/x-8 - x-8/x-9求x=? 用递归法求y=x-(x*x*x/3!)+(x*x*x*x*x/5!)-(x*x*x*x*x*x*x/7!)+. （X+X)+(X-X)+(X*X)+(X/X)=100 X-5+8*X=7*X-2*X-1 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), 已知1+x+x^2+x^3=0,求x+x^2+x^3+x^4+x^5+x^6+x^7+x^8的值 求方程解x-5/x-4+x-9/x-8=x-8/x-7+x-6/x-5 x-4/x-5-x-7/-x-8=x-5/x-6-x-8/x-9 解分式方程：(x-4)/(x-5)+(x-8)/(x-9)=(x-7)/(x-8)+(x-5)/( x-6)