import math

def quadratic_equation(a, b, c):

? ? de = b**2 - 4*a*c

? ? if de>=0:

? ? ? ? ?x1 = (-b+math.sqrt(de))/(2*a)

? ? ? ? ?x2 = (-b-math.sqrt(de))/(2*a)

? ? ? ? return x1, x2

? ? else:

? ? ? ? return

print quadratic_equation(2, 3, 0)

print quadratic_equation(1, -6, 5)