import math
def quadratic_equation(a, b, c):
    if b**2 - 4*a*c > 0:
        x = (-b + math.sqrt(b**2 - 4*a*c))/(2*a)
        y = (-b - math.sqrt(b**2 - 4*a*c))/(2*a)
        return x, y
    else:
        if b**2 - 4*a*c = 0:
            x = (-b)/(2*a)
            return x
        else:
            return

print quadratic_equation(2, 3, 0)
print quadratic_equation(1, -6, 5)