我还有两个不会诶 4x-2(50-x)=20 2x+5x+10(50-2x)=240
x^5+x^4 = (x^3-x)(x^2+x+1)+x^2+x
x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少?
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),
5*(x-2)=4*(x+3) 2x+(50-x)*4=140 3x-(8-x)=20*4 200x=(x-0.5)*2
(x+12)(x-2)+(x+7)(x+8)-(x+5)(x-10),其中x=2
2x+3x+4x+5x+x+6x+7x=100
解方程(x/x(x+2))+(x/(x+2)(x+4))+.+x/(x+8)(x+10)=1
1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550
X-2分之X=X-5分之X-4怎么解?还有X减3分之X等于X减1分之X+1
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