Bonsoir
a = 18x² - 24x +54
b = 8x - 9x² +4x = -9x² +12x
c = 5x - 21x +14 = - 16x +14
d = 35x² -28x -18x +14x² = 49x² - 46x
a = 18x -16x² + (20x² +12x -5x -3)
a = -16x² +18x +20x² +12x -5x -3
a = 4x² +25x -3
b = 28x -7x² -4 +x -30x² +15x
b = -37x² +44x -4
c = -30x² -35x +42+49 - (3x² -3x + 8x -8)
c = -30x² -35x + 91 -3x² +3x -8x +8
c = -33x² -40x + 99
d = 21x² +14x -35 +3x² +6x -3x -6
d = 24x² +17x - 41
