Réponse :
Bonjour
(x + 1)(x + 2) = x² + 2x + x + 2 = x² + 3x + 2
(x - 1)(3 - x) = 3x - x² - 3 + x = -x² + 4x - 3
(x² + 1)(2x - 1) = 2x³ - x² + 2x - 1
(1 - x)(2 - x²) = 2 - x² - 2x + x³ = x³ - x² - 2x + 2
(x + 1)(x + 2) + (x + 1)(x - 3) = (x + 1)(x + 2 + x - 3) = (x + 1)(2x - 1)
(2x + 1)(x² + x) + (2x + 1)(3 - 2x) = (2x + 1)(x² + x + 3 - 2x) = (2x + 1)(x² - x + 3)
x²(x + 1) + x²(2x² - 1) = x²(x + 1 + 2x² - 1) = x²(2x² + x)
