Réponse :
Salut,
D = 16x - 28y
= 4 * 4 * x - 4 * 7 * y
= 4(4x - 7y)
E = 16x² - 28xy
= 4 * 4 * x² - 4 * 7 * xy
= 4x(4x - 7y)
F = 24x² + 9y - (5 - x² - y)
= 24x² + 9y - 5 + x² + y
= 25x² + 10y - 5
= 5 * 5 * x² + 5 * 2 * y - 5
= 5(5x² + 2y - 1)
G = 4(5x² - 2y) + 5(x² - 2y) + 8y
= 20x² - 8y + 5x² - 10y + 8y
= 25x² - 10y
= 5 * 5 * x² - 5 * 2 * y
= 5(5x² - 2y)
