(x+1)/(x-1)-1=4/(x+1)(x-1)
两边乘(x+1)(x-1)
(x+1)²-(x+1)(x-1)=4
x²+2x+1-x²+1=4
2x=-2
x=-1
经检验,x=-1时分母(x+1)(x-1)=0
增根,舍去
方程无解
解分式方程：（x+1/x-1）-1=4/x²-1.
(x+1)/(x-1)-1=4/(x+1)(x-1)
两边乘(x+1)(x-1)
(x+1)²-(x+1)(x-1)=4
x²+2x+1-x²+1=4
2x=-2
x=-1
经检验,x=-1时分母(x+1)(x-1)=0
增根,舍去
方程无解