8(3x-1)-9(5x-1)-2(2x-7)=30

|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 1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550 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 x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? 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 (3-x)/(1-x)-(5-x)/(7-x)+(x^2-x)/(x^2-8x+7)=1 x+2/x+3－x+1/x+2=x+8/x+9－x+7/x+8 (X+2)/(X+1)-(X+4)/(X+3)=(X+6)/(X+5)-(X+8)/(X+7)