900+x=(10x+9)×4-111 (1200+x)×6+802=100x+12 (1000+10x+4)+549=
(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
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),
x-4/x-6+x-8/x-10=x-5/x-7+x-7/x-9
解方程:(x-8)/(x-3)-(x-9)/(x-4)=(x+7)/(x+8)-(x+2)/(x+3)
3/x-1=4/x 6/x+1=x+5/x(x+1)
(x+1分之x+6)-(x^+3x+2分之3x^+10x+4)+(x+2分之2x+1)=0,解这个方程
解方程.(5x/x²+x-6)+(2x-5/x²-x-12)=7x-10/x²-6x+8
1、x*(x+3)*(x+6)*(x+9)=68040 2、x*(x+1)*(x+2)*(x+3)*(x+4)=5544
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