题目内容：

先化简,再求值 {X-1分之3X-X+1分之X}乘X分之X方-1,其中X=根号2-2

优质解答

[3x/(x-1)-x/(x+1)]×(x²-1)/x
=x[3(x+1)-(x-1)]/(x²-1)×(x²-1)/x
=2x+4
当x=√2-2时,原式=2x+4=2√2