dau coroana si 5 stelem.........

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