Bonjour,
A = 5x (x + 1)
A = 5x² + 5x
B = (x + 2) (2x + 1)
B = 2x² + x + 4x + 2
B = 2x² + 5x + 2
C = (3 - 2x) (x - 8)
C = 3x - 24 - 2x² + 16x
C = - 2x² + 19x - 24
D = (x - 3)²
D = x² - 6x + 9
E = 8 (x + 2) + (4x + 1) (2x - 3)
E = 8x + 16 + 8x² - 12x + 2x - 3
E = 8x² + 8x + 2x - 12x + 16 - 3
E = 8x² - 2x + 13.
