Répondre :
Bonsoir
1)
E = (12+3x)(2x-7) -(2x-7)²
E = 24x-84+6x²-21x-(4x²+49-28x)
E = 2x²+31x-133
2)
E = (2x-7)( 12+3x-2x+7)
E = (2x-7)(x+19)
4)
(2x-7)(x+1) = 0 si un des facteurs = 0
2x-7 = 0 si x = 7/2
x+1 = 0 si x = -1
Bonsoir
1)
E = (12+3x)(2x-7) -(2x-7)²
E = 24x-84+6x²-21x-(4x²+49-28x)
E = 2x²+31x-133
2)
E = (2x-7)( 12+3x-2x+7)
E = (2x-7)(x+19)
4)
(2x-7)(x+1) = 0 si un des facteurs = 0
2x-7 = 0 si x = 7/2
x+1 = 0 si x = -1