原式=[2x(x+1)/(x+1)(x-1)-x(x-1)/(x-1)²]÷x/(x+1)=[2x/(x-1)-x/(x-1)]×(x+1)/x=x/(x-1)×(x+1)/x=(x+1)/(x-1)当x=1+√2时原式=(2+√2)/(1+√2-1)=√2 +1若(x+1)/(x-1)=-1则x+1=-x+1x=0但x=0时 x/(x+1)=0 成...