import numpy as np

def fun_losn_2grads_likn(a, b, c):
    x1 = (b + np.sqrt(b*b - 4*a*c))/(2*a)
    x2 = (- b + np.sqrt(b*b - 4*a*c))/(2*a)
    return (x1, x2)


a = 1
b = 0
c = -4

(x1, x2) = fun_losn_2grads_likn(a, b, c)
print('x1 =', x1)
print('x2 =', x2)