(x+1/x-1 - x-1/x+1)(x^2-1)/4x = ((x+1)^2 - (x-1)^2/x^2-1)(x^2 - 1)/4x = (x^2 + 2x + 1 - x^2 + 2x - 1)/4x = 4x/4x = 1
(x+1/x-1 - x-1/x+1)(x^2-1)/4x = ((x+1)^2 - (x-1)^2/x^2-1)(x^2 - 1)/4x = (x^2 + 2x + 1 - x^2 + 2x - 1)/4x = 4x/4x = 1