7-4x+9=30

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=? (4x+2)/x+(4x-22)/(x-5)=(x-6)/(x-4)+(7x+9)/(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 x-4/x-6+x-8/x-10=x-5/x-7+x-7/x-9 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 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