Réponse :

Bonjour

Explications étape par étape

Question 1

A = 4x ( 8x -7) + (4 -3x) (5 +3x)

A = 32x² -28x + 20 +12x -15x -9x²

A = 23 x² -31x +20

Question 2

Factorisation

B = (5 +2x)(4 +3x) - (5 +2x) (7 +x)

B = (5 +2x) (4 +3x -7 -x)

B = (5 +2x) ( 2x -3)

Question 3

Equation

5 + 8 (3x -3) = 4x -9

5 +24x -24 = 4x -9

+24x -4x = -5 +24 -9

+20x = 10

x = 10/20

x = 1/2