[tex]b) \frac{2x-1}{x^3-1}-\frac{x}{x-1}+1= \frac{2x-1-x( x^{2}+x+1)+ x^{3}-1}{x^3-1}=\frac{2x-1- x^{3}- x^{2}-x+x^3-1}{x^3-1}= \\=\frac{-x^2-x-2}{x^3-1}[/tex]
Am folosit formula de calcul prescurtat:
[tex]a^3-b^3=(a-b)(a^2+ab+b^2)[/tex]
[tex]x^3-1^3=(x-1)(x^2+x+1)[/tex]
