Réponse :
Explications étape par étape
Bsr
A = 3(4x + 7) + 4(2x - 9)
= 12x + 21 + 8x - 36
= 20x - 15
= 5 × 4x - 5 × 3
A = 5 (4x - 3 )
B = 7x(2x - 5) - x(2x-5)
= (2x-5) (7x-x)
= 14x² - 2x² - 35x + 5x
= 12x² - 30x
= 6 ×2 × x × x - 6 × 5 × x
B = 6x ( 2x - 5x )
