Bonjour,
Exercice 3 :
A = (4x - 8) - (3x - 7) + (-2x + 3)
A = 4x - 8 - 3x + 7 - 2x + 3
A = -x + 2
B = (6x² - 5x + 7) - (4x² - 5x - 5)
B = 6x² - 5x + 7 - 4x² + 5x + 5
B = 2x² + 12
C = - (3x² - 5x + 2) + (2x² - 2x + 8) - (3 - 2x + 2x²)
C = -3x² + 5x - 2 + 2x² - 2x + 8 - 3 + 2x - 2x²
C = -3x² + 5x + 3
Exercice 4 :
A = (4x + 5)(3x + 2)
A = 12x² + 8x + 15x + 10
A = 12x² + 23x + 10
B = (5x - 2)(x + 7)
B = 5x² + 35x - 2x - 14
B = 5x² + 33x - 14
C = (4x - 3)(5x - 2)
C = 20x² - 8x - 15x + 6
C = 20x² - 23x + 6
Exercice 5 :
A = (6x - 4) - (2x - 8)
A = 6x - 4 - 2x + 8
A = 4x + 4
B = (6x - 4)(2x - 8)
B = 12x² - 48x - 8x + 32
B = 12x² - 56x + 32
C = (6x - 4) + (2x - 8)
C = 6x - 4 + 2x - 8
C = 8x - 12
D = 6x - 4 (2x - 8)
D = 6x - 8x + 32
D = -2x + 32
