5x+3.5×4=38 16x-2x=7 5（x+7）=35 6x+4x=52 20÷（x-6）=4 7x-15=4x

x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? （1） x-3/x-2 - x-5/x-4=x-7/x-6 - x-9/x-8 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=? 1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550 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), (4x+2)/x+(4x-22)/(x-5)=(x-6)/(x-4)+(7x+9)/(x+1) 解方程(x-2)/(x-3)-(x-3)/(x-4)=(x-5)/(x-6)-(x-6)/(x-7) 解方程:(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