Пример D

from math import sqrt
m=[1,2,3,4,5,6,7,8,9]
m[3]=[1,2,1]
a=m[3][0]
b=m[3][1]
c=m[3][2]
def f(a,b,c):

    D=b*b-4*c*a
    if D<0:
        print None
        return

    X1=(-b+sqrt(D))/(2*a)
    X2=(-b-sqrt(D))/(2*a)
    print  "Korni",X1,X2
f(a,b,c)







from math import sqrt
def f(a,b,c):
    d=b*b-4*a*c
    if d<0:
        print None
        return
    x_1=(-b+sqrt(d))/(2*a)
    x_2=(-b-sqrt(d))/(2*a)
    print x_1, x_2
#f(a,b,c)
Coefs = [[1,2,1], [3,4,-5], [4,4,-4], [2,2,0]]
i = 0
while i < 4:
    coefi = Coefs[i]
    G = coefi[0]
    H = coefi[1]
    J = coefi[2]
    f(G, H, J)
    i += 1