Bonjour,

Explications étape par étape :

A = 3x² + 2x + (3x + 2)²

A = x(3x + 2) + (3x + 2)²

A = (3x + 2)(x + 3x + 2)

A = (3x + 2)(4x + 2)

B = (4x + 3)² - 4x - 3

B = (4x + 3)² + (- 4x - 3)

B = (4x + 3)² - (4x + 3)

B = (4x + 3)(4x + 3 - 1)

B = (4x + 3)(4x + 2)

C = (x - 5)(2x + 3) - x² + 25

C = (x - 5)(2x + 3) - (x² - 5²)

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

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

C = (x - 5)(x - 2)