Réponses

Meilleure réponse !
2014-09-30T18:52:34+02:00
A = (3x-2)(7x+3) +(5x-7)(3x-2)             Développement
A = (21x² +9x -14x -6) + (15x² -10x -21x +14)
A = 21x² -5x -6 + 15x² -31x +14
A = 36x² -36x -8

Factorisation
A = (3x-2)(7x+3) + (5x-7)(3x-2)
(3x-2) (7x+3 +5x-7)
(3x-2) (+12x -4)

x = -2
(3x-2)(12x-4)
(3 X -2 -2) (12 X-2 -4)
(-6 -2)( -24 -4)
-8 X -28 = -224

x = 0
(3x-2)(12x -4)
3X0 -2)(12 X0 -4)
(0 -2)(0 -4)
+8