2/3x=3.9+1/5x

x^5+x^4 = (x^3-x)(x^2+x+1)+x^2+x 解方程x/(x-2)=2x/(x-3)+(1-x)/(x-5x+6) (2x-1)/(x-1)(x-2)=(x-5)/(x-2)(x-3) x/2x^2-11x-21=(x+7)/x^2-1 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 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 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), (3-x)/(1-x)-(5-x)/(7-x)+(x^2-x)/(x^2-8x+7)=1 解方程(x+1/x+2)-(x+2/x+3)=(x+5/x+6)-(x+6/x+7) 解方程：x+2/x+1-x+3/x+2=x+6/x+5-x+7/x+6 x-1\x-2+x-6\x-7=x-2\x-3+x-5\x-6 分式方程 （1） x-3/x-2 - x-5/x-4=x-7/x-6 - x-9/x-8 1x+2x+3x+4x+5x+6x+7x…+99x=100