x^2 - 120x + 2000 = 0
On calcule le discriminant :
Delta^2 = (-120)^2 - 4 * 1 * 2000
Delta^2 = 14400 - 8000
Delta^2 = 6400
Delta = V6400
Delta = 80 > 0 donc deux solutions
X1 = (120 - 80) / (2 * 1)
X1 = 40 / 2
X1 = 20
X2 = (120 + 80) / (2 * 1)
X2 = 200 / 2
X2 = 100
