是化简么?
(x+1)/x × [2x/(x+1)]^2 - [1/(x-1) - 1/(x+1)]
=(x+1)/x 4x^2/(x+1)^2 - (x+1-x+1)/(x-1)(x+1)
=4x/(x+1) -2/(x^2-1)
=[4x(x-1) - 2]/(x^2-1)
=(4x^2-4x-2)/(x^2-1)