Exercice 2 : Factoriser les expressions suivantes : A = (x - 3)(2x + 1) + 7(2x + 1) B = (x + 1)(x + 2)-5(x + 2) C = (3 - x)(4x + 1) - 8(4x + 1) D = 5(1 + 2x) -

Réponse :

Explications étape par étape

Bsr,

repère ce qui est commun:

A = (x - 3)(2x + 1) + 7(2x + 1)

B = (x + 1)(x + 2)-5(x + 2)

C = (3 - x)(4x + 1) - 8(4x + 1)

D = 5(1 + 2x) - (x + 1)(1 + 2x)

E = -6(3x - 2) - (3x - 2)(x - 4)

A = (x - 3)(2x + 1) + 7(2x + 1) = (2x+1)( x-3 +7) = (2x+1) ( x+4)

B = (x + 1)(x + 2)-5(x + 2) = (x+2) ( x+1 -5) = (x+2) ( x-4)

C = (3 - x)(4x + 1) - 8(4x + 1) = (4x+1) ( 3-x -4x-1) = (4x+1) ( -5x +2)

D = 5(1 + 2x) - (x + 1)(1 + 2x) = (1+2x) (5 -x-1 ) = (1+2x ) (-x +4)

E = -6(3x - 2) - (3x - 2)(x - 4) = (3x-2) ( -6 -x+4)= (3x-2) (-x -2)

☺