Bonjour
Développe puis réduis chaque expression :
D = 7x(2x – 5) – x(2x – 5)
D = 14x² - 35x - 2x² + 5x
D = 14x² - 2x² - 35x + 5x
D = 12x² - 30x
E = (2x – 5)(3x – 2)
E = 6x² - 4x - 15x + 10
E = 6x² - 19x + 10
F = (x + 7)(3 – 2x) + (5x – 2)(4x + 1)
F = 3x - 2x² + 21 - 14x + 20x² + 5x - 8x - 2
F = - 2x² + 20x² + 3x + 5x - 8x - 14x + 21 - 2
F = 18x² - 14x + 19
G =(5x + 4)(2x + 3) – (5x + 7)
G = 10x² + 15x + 8x + 12 - 5x - 7
G = 10x² + 15x + 5x - 5x + 12 - 7
G = 10x² + 15x + 5.