解[(x²-1)/(x²-2x+1)×(x-1)/(x²+x)]+2/x=[(x-1)(x+1)/(x-1)²×(x-1)/x(x+1)]+2/x=[(x+1)/(x-1)×(x-1)/x(x+1)]+2/x=1/x+2/x=3/x
