由式1,得2t²=1-(t/x)
代入式2得：y=(1-1+t/x)/(1+1-t/x)=(t/x)/(2-t/x)=t/(2x-t)
解得t=2xy/(y+1)
再代入式1：x=2xy/(y+1)/[1-8x²y²/(y+1)²]
化简得：：y²(1+8x²)=1