Question

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

Answer 1

$3x^2-x-2=3x^2-3x+2x-2=3x(x-1)+2(x-1)=$

$=(x-1)(3x+2)$

SAU:

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

$ax^2+bx+c=a(x-x_1)(x-x_2)$.  Obtii:

$3x^2-x-2=3(x-1)(x+\dfrac23)=(x-1)(3x+2)$