1-1/3(6x+9)=3(x+2/3)
|X-1|+|X-2|+|X-3|+|X-4|+|X-5|+|X-6|+|X-7|+|X-8|+|X-9|+|X-10|
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),
(1) x-3/x-2 - x-5/x-4=x-7/x-6 - x-9/x-8
2x/x^2-9=x-1/x^2-6x+9-1/x+3
(x-2)(x2-6x-9)-x(x-5)(x-3)其中x= -1/3
1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550
解方程x/(x-2)=2x/(x-3)+(1-x)/(x-5x+6)
x+2/x^2-x-6 + 2x/x^3-3x - x+1/x^2-6x+9
(x+2/x^2-x-6)-(2x/x^2-3x)-(x+1/x^2-6x+9)
1x()+2x()+3x()+4x()+5x()+6x()+7x()+8x()加9x()+10x()=1980
1X?+2X?+3X?+4X?+5X?+6X?+7X?+8X?+9X?+10X?=1980求?是多少