Răspuns:
[tex] \frac{(2x + 1) {}^{2} - (2x - 1) {}^{2} }{(x - 1) {}^{2} - (x + 1 {}^{2}) } [/tex]
[tex] \frac{4x {}^{2} + 4x + 1 - (4 x{}^{2} - 4x + 1)}{(x {}^{2} - 2x + 1) - (x {}^{2} + 2x + 1) } [/tex]
[tex] \frac{4x {}^{2} + 4x + 1 - 4x {}^{2} + 4x - 1 }{x {}^{2} - 2x + 1 - x {}^{2} - 2x - 1} [/tex]
[tex] \frac{8x}{ - 4x} [/tex]
[tex] - 2[/tex]
