Réponse :
Explications étape par étape
(6x-5)² = 36x²-60x+25 forme (a-b)² = a²-2ab+b²
Factorisations:
A (-5x-5)x+x(-8x-9)
⇔x(-5x-5-8x-9)
⇔x(-13x-14)
B 49x²-64 forme a²- b² = (a+b) (a-b)
(7x+8) (7x-8)
C 49x²-49 forme a²- b² = (a+b) (a-b)
⇔ (7x+7) (7x-7)
D (9x-7) .5x+7 (9x-7) = (9x-7) (5x+7)
E 9x²-4 forme a²- b² = (a+b) (a-b)
⇔(3x+2) (3x-2)
F (4x-6) (9x-3) +7 (4x-6) = (4x-6) (9x-3+7) = (4x-6) (9x+4)
G 16x²-4 forme a²- b² = (a+b) (a-b)
⇔ (4x+2) (4x-2)
H (-8x-2) (4x+6) +4 (-8x-2)
⇔ (-8x-2) (4x+6-4) = (-8x-2) ( 4x+2)
