2（3X+5）=7X

（1） x-3/x-2 - x-5/x-4=x-7/x-6 - x-9/x-8 x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? 初一数学x*x+2x+5的值为7,请求3x*x+6x+3的值.因为x*x+2x2x+3=3x（x*x+2x）+2x+2x 2x+3x+4x+5x+x+6x+7x=100 5x/(x+3)(x+2)+（2x-5）/(x-4)(x+3)=（7x-70）/(x+2)(x+4) 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!)+. (2x-1)/(x-1)(x-2)=(x-5)/(x-2)(x-3) x/2x^2-11x-21=(x+7)/x^2-1 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 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), (3-x)/(1-x)-(5-x)/(7-x)+(x^2-x)/(x^2-8x+7)=1 解方程(x-2)/(x-3)-(x-3)/(x-4)=(x-5)/(x-6)-(x-6)/(x-7)