Réponses

2013-09-22T08:01:40+02:00
D(x) = (3x-7)² - (4-2x)²
D(x) = 9x² - 42x + 49) - (16 - 16x + 4x²)
D(x)= 9x² -42x + 49 -16 +16x -4x²
D(x) = 5x² -26+33