Bonjour
A (x) = 5x (2x + 3) - 10
A (x) = 10x² + 15x - 10
B (x) = - 3x + 7 (2x - 1)
B (x) = - 3x + 14x - 7
B (x) = 11x - 7
C (x) = 3 (4x - 1) - (x + 1) (- 5x + 4)
C (x) = 12x - 3 - (- 5x² + 4x - 5x + 4)
C (x) = 12x - 3 + 5x² - 4x + 5x - 4
C (x) = 5x² + 12x + 5x - 4x - 3 - 4
C (x) = 5x² + 13x - 7.
