7x\0.9+4x\8=4.2

x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? X 7 X - X 7 X = X 9 8 X 9 X - X 9 X = 4 9 x-4/x-5 - x-5/x-6=x-7/x-8 - x-8/x-9求x=? 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 已知1+x+x^2+x^3=0,求x+x^2+x^3+x^4+x^+x^6+x^7+x^8的值 x-4/x-6+x-8/x-10=x-5/x-7+x-7/x-9 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)