Réponses

2012-10-08T21:48:30+02:00

9x - x² = 18 - 9x + x²

 

9x - x² - 18 + 9x - x²

 

-2x² + 18 x - 18 = 0

-x² + 9x - 9 = 0

 

delta = 81 -4 (9) = 45

 

racine (delta) = rac(45) = rac(9*5) = 3 rac 5

 

x1 = (-9 - 3 rac 5) / -2

x2 = (-9 + 3 rac 5) / -2