若√(7-2)²=x-7,√(x-13)²=13-x,化简:│6-x│+│x-16│
(x-2)(x-3)+2(x+6)(x-5)-3(x²-7x+13)化简
解方程.(5x/x²+x-6)+(2x-5/x²-x-12)=7x-10/x²-6x+8
1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550
若x=(-1±√13)/2,求X³+3X²-X-6的值.
0.3x²+x=0.8 x²+3=2√3x x²+2x-2=0 3x²+4x-7
18/2X+9=54/7x为什么x=27及为什么x√x²+2x+1被化简为x|x+1|.
x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少?
(1) x-3/x-2 - x-5/x-4=x-7/x-6 - x-9/x-8
解方程(x²-x+4)x-(x-1)(x²+2)=x+7
解方程x²+x-6分之5x+x²-x-12分之2x-5=x²-6x+8分之7x-10
已知2x*x+x-5=0,求代数式6x*x*x+7x*x-13x+11的值
2x+3x+4x+5x+x+6x+7x=100