[tex] \frac{1-x }{1+x} + \frac{1+x}{1-x} + \frac{4x}{x^2 - 1} = \frac{2(1-x)}{1+x}
[/tex]
[tex] \frac{1-x}{1+x} + \frac{1+x}{1-x} + \frac{4x}{x^2-1} = \frac{2-2x}{1+x} [/tex]
[tex] \frac{1-x}{1+x} + \frac{1+x}{1-x} + \frac{4x}{x^2-1} - \frac{2-2x}{1+x} = 0[/tex]
[tex] \frac{1-x}{1+x} + \frac{1+x}{-(x-1)} + \frac{4x}{(x-1)(x+1)} - \frac{2-2x}{1+x} = 0 [/tex]
[tex] \frac{-(x-1)^2 - (1+x)^2 + 4x - ( 4x - 2x^2 - 2 ) }{(x-1)(x+1)} = 0 [/tex]
[tex] \frac{-x^2+2x-1-1-2x-x^2 + 2x^2 + 2 }{(x-1)(x+1)} = 0 [/tex]
[tex] \frac{0+0}{(x-1)(x+1)} = 0[/tex]
[tex]0 = 0
[/tex] ( Adevărat )
