(x²-1)/(x²+x)÷[x-(2x-1)/x]
=(x²-1)/(x²+x)÷[(x²-2x+1)/x]
=(x²-1)/(x²+x)÷[(x-1)²/x]
=(x²-1)/(x²+x)*x/(x-1)²
=(x-1)(x+1)/[x(x+1)]*x/(x-1)²
=1/(x-1)
=1/(√2+1-1)
=1/√2
=√2/2對(duì)不起，式子應(yīng)該是這樣滴x²-1/x²+x÷{x-【2x-1/x】}，其中X=根號(hào)2+1