Ответ:

[tex]3-x^{2}[/tex]

Пошаговое объяснение:

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

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

[tex]\displaystyle=(x^{2} -1)(\frac{x+1-x+1-x^{2} +1}{(x-1)(x+1)} =(x^{2} -1)(\frac{3-x^{2} }{(x-1)(x+1)} )=\displaystyle[/tex]

[tex]\displaystyle=(x^{2} -1)*\frac{3-x^{2} }{x^{2} -1} =3-x^{2}[/tex]