若√(7-x)²=x-7,√(x-13)²=13-x,试化简|6-x|+|x-16|
解方程.(5x/x²+x-6)+(2x-5/x²-x-12)=7x-10/x²-6x+8
(1) x-3/x-2 - x-5/x-4=x-7/x-6 - x-9/x-8
(x-2)(x-3)+2(x+6)(x-5)-3(x²-7x+13)化简
若x=(-1±√13)/2,求X³+3X²-X-6的值.
1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550
初一数学x*x+2x+5的值为7,请求3x*x+6x+3的值.因为x*x+2x2x+3=3x(x*x+2x)+2x+2x
根号7(x²-x)=根号5(x²+x)
求y=√(x²-6x+13)+√(x²+4x+5)及y=√(x²-6x+13)-√(x
已知X+1/X=√5,则X²+1/X²=(?),X-1/X=(?)
解方程:(13x-x²)/(x+1)·[x+(13-x)/(x+1)]=42.
f(x)=x²+3x|x-2|
已知x²+8x-13=0,求(x+2)(x-2)-4x(x-1)+(2x+1)²的值