Réponse :

a) (3x+2)²= (3x+7)(3x+7)=9x²+21x+21x+49 = 9x²+42x+49

b) (5x-6)² = (5x-6)(5x-6) = 25x² - 30x - 30x + 36 = 25x² - 60x +36

c) (6x+ 8)(6x-8 ) =  36x²- 64

d) ( 7x+5 )² = (7x + 5)(7x +5 ) = 49x² + 35x + 35x + 25 = 49x²  + 70x + 25

e) (6-2x )² = (6-x )(6-x ) = 36 - 6x - 6x + x² = 36 - 12x + x²

f) (5-2x)(5+2x) = 25 + 10x - 10x - 4x²  = 25 - 4x²

Explications étape par étape :

Réponse :

a) (3x + 7)^2 = 9x^2 + 42x + 79

b) (5x - 6)^2 = 25x^2 - 60x + 36

c) (6x + 8)(6x - 8) = 36x^2 - 64

d) (7x + 5)^2 = 49x^2 + 70x +25

e) (6 - x)^2 + 36 - 12x + x^2

f) (5 - 2x)(5 + 2x) = 25 - 4x^2