Bonjour,
A = 5 (2x + 1) - 3 (x + 2)
A = 10x + 5 - 3x - 6
A = 10x - 3x + 5 - 6
A = 7x - 1
B = 6 - (3x - 1) - (7x + 2)
B = 6 - 3x + 1 - 7x - 2
B = - 3x - 7x + 6 + 1 - 2
B = - 10x + 5
C = 4 (5x + 9) + (8x - 9)
C = 20x + 36 + 8x - 9
C = 20x + 8x + 36 - 9
C = 28x + 27
D = - (6x - 3) - (- 4x + 1) + 2 (8x - 7)
D = - 6x + 3 + 4x - 1 + 16x - 14
D = - 6x + 4x + 16x + 3 - 1 - 14
D = 14x - 12.
