2x^2 -5x +2 = 0
a=2
b=-5
c=2
delta = b^2 -4ac
delta = (-5)^2 -4*2*2
delta = 25 -16
delta = 9
delta > 0 alors l’équation à 2 solutions réelles : x1 et x2
x1 = (-b - racine de delta) / 2a
x1 = (5 - racine de 9) / 4
x1 = (5 -3) / 4
x1 = 2/4
x1 = 1/2
x2 = (b - racine de delta) / 2a
x2 = (-5 - racine de 9) / 4
x2 = (-5-3) / 4
x2 = -8/4
x2 = -2
