Sagot :
Réponse :
Bonsoir,
(2x + 1)² - (2x + 1)(x + 3)
= (2x + 1)(2x + 1) - (2x + 1)(x + 3)
= 2x * 2x + 2x * 1 + 1 * 2x + 1 * 1 - 2x * x + 2x * 3 + 1 * x + 1 * 3
= 4x² + 2x + 2x + 1 - 2x² + 6x + 1x + 3
= 2x² - 3x - 2
Réponse :
(2x + 1)² - (2x + 1)(x + 3)
= (2x + 1)(2x + 1) - (2x + 1)(x + 3)
= 2x * 2x + 2x * 1 + 1 * 2x + 1 * 1 - 2x * x + 2x * 3 + 1 * x + 1 * 3
= 4x² + 2x + 2x + 1 - 2x² + 6x + 1x + 3
= 2x² - 3x - 2