Réponses

2013-01-16T11:43:14+01:00

x² - 20x - 400 = x² - 20x +100 -500= (x-10)² - 500
x^3 > (x+20)²)(x-20) x^3 > x^3 + 20x² + 400x -8000 0> 20(x² + 20x - 400) x² + 20x - 400<0