Bonjour,
A= (x - 3)(x + 4) + (3x + 2)(x+5)
A= (x² + 4x - 3x - 12) + (3x² + 15x + 2x + 10)
A= (x² + x - 12) + (3x² + 17x + 10)
A= 4x² + 18x - 2
B = (2x + 3)(5x - 7) - (4 - 5x)(2x + 1)
B = (10x² - 14x + 15x - 21) - (8x + 4 - 10x² - 5x)
B = (10x² + x - 21) - (3x + 4 - 10x²)
B = 20x² - 2x - 25
