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buna! imi explica si mie cineva descompunerea in factori de la 3x²-x -2.....

Răspuns :

[tex]3x^2-x-2=3x^2-3x+2x-2=3x(x-1)+2(x-1)=[/tex]

[tex]=(x-1)(3x+2)[/tex]

SAU:

Rezolvi ecuatia [tex]3x^2-x-2=0;\ \ \Delta=25;\ \ x_1=1;\ \ \ x_2=-\dfrac23[/tex] si folosesti formula:

[tex]ax^2+bx+c=a(x-x_1)(x-x_2)[/tex].  Obtii:

[tex]3x^2-x-2=3(x-1)(x+\dfrac23)=(x-1)(3x+2)[/tex]