6@2=6+7,9@4=9+11+12+13=42,那么x@5=20,则x=?
1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550
x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少?
如果3x*x-x=1那么9x*x*x*x+12x*x*x-3x*x-7x+2001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
(4x+2)/x+(4x-22)/(x-5)=(x-6)/(x-4)+(7x+9)/(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),
解方程:(x+3)/(x+2)-(x+5)/(x+4)=(x+7)/(x+6)-(x+9)/(x+8)
(1) x-3/x-2 - x-5/x-4=x-7/x-6 - x-9/x-8
如果2x+1=9,那么6x+1.5x+11等于( )
x-4/x-5 - x-5/x-6=x-7/x-8 - x-8/x-9求x=?
a*b=2×a+b 计算x*2x*3x*4x*5x*6x*7x*8x*9x=3039 x=
1x()+2x()+3x()+4x()+5x()+6x()+7x()+8x()加9x()+10x()=1980