Bonjour !
G = (4x+1)(x-3)-(x-3)(2x+5)
Développer et réduire :
4x²-12x+x-3 - (2x²+5x-6x-15)
4x²-12x+x-3-2x²-5x+6x+15
G = 2x²-10x+12
Factoriser
G = 2x²-10x+12
Delta = 10²- 4×(2×12) = 4
X¹ => 10+2/4 = 12/4 = 3
x² = 10-2/4 = 8/4 = 2
2(x+3)(x+2)
Résoudre G = 0
2(x+3)(x+2) = 0
(x+3) = 0 => x = - 3
(x+2) = 0 => x = -2
S = (-2;-3)
Bon courage
