(X-Y/X+2Y)÷[(X²-Y²/X²+4XY+4Y²)-2]其中x=2+根号3,y=2-根号3.X-Y/X+2Y÷X²-Y²/X²+4XY+4Y²-2 其中x=2+根号3，y=2-根号3.上面的不算

(X-Y/X+2Y)÷[(X²-Y²/X²+4XY+4Y²)-2]其中x=2+根号3,y=2-根号3.X-Y/X+2Y÷X²-Y²/X²+4XY+4Y²-2 其中x=2+根号3，y=2-根号3.上面的不算
(X-Y/X+2Y)÷[(X²-Y²/X²+4XY+4Y²)-2]其中x=2+根号3,y=2-根号3.
X-Y/X+2Y÷X²-Y²/X²+4XY+4Y²-2 其中x=2+根号3，y=2-根号3.上面的不算

(X-Y/X+2Y)÷[(X²-Y²/X²+4XY+4Y²)-2]其中x=2+根号3,y=2-根号3.X-Y/X+2Y÷X²-Y²/X²+4XY+4Y²-2 其中x=2+根号3，y=2-根号3.上面的不算
X-Y/X+2Y÷X²-Y²/X²+4XY+4Y²-2
=(X-Y/X+2Y)*(X+2y)^2/(x+y)(x-y)-2
=x+2y/x+y-2
=x+2y-2x-2y/x+y
=-x/x+y
=-(2+√3)/(2+√3+2-√3 )
=-(2+√3)/4

检查一下题目