4x-(20-x)=5x+6(7-x)

x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? 2x+3x+4x+5x+x+6x+7x=100 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 (4x+2)/x+(4x-22)/(x-5)=(x-6)/(x-4)+(7x+9)/(x+1) x-4/x-6+x-8/x-10=x-5/x-7+x-7/x-9 解分式方程 x-7/x-9+x-3/x-5=x-4/x-6+x-6/x-8 解方程(x-2)/(x-3)-(x-3)/(x-4)=(x-5)/(x-6)-(x-6)/(x-7) 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