[code python]сюда вставлять код, чтобы правильно отображался[/code]

 import numpy as np
def solve_with_rotation(m):
    """Solve system with rotation method.
    :param m: numpy matrix
    :return: None
    """
    n = m.shape[0]
    # forward trace
    for i in range(n-1):
        for j in range(i + 1, n):
            c = m[i, i] / (m[i, i]**2 + m[j, i]**2) ** .5
            s = m[j, i] / (m[i, i]**2 + m[j, i]**2) ** .5
            tmp1 = m[i, :] * c + m[j, :] * s
            tmp2 = m[i, :] * -s + m[j, :] * c
            m[i, :] = tmp1
            m[j, :] = tmp2
    # check for non-singularity
    if is_singular(m):
        print('The system has infinite number of answers...')
        return
    # backward trace
    x = np.matrix([0.0 for i in range(n)]).T
    for k in range(n - 1, -1, -1):
        x[k, 0] = (m[k, -1] - m[k, k:n] * x[k:n, 0]) / m[k, k]
    # Display results
    print('ответ :\n{:f}\n{:f}\n{:f}'.format(x.item(0), x.item(1), x.item(2)))
def is_singular(m):
    """Check matrix for nonsingularity.
    :param m: matrix (list of lists)
    :return: True if system is nonsingular
    """
    return np.any(np.diag(m) == 0)
m = np.matrix(
    '2 -9 5 -4;'
    '1.2 -5.3999 6, 0.6001;'
    '1 -1 -7.5 -8.5'
)
print(m)
solve_with_rotation(m)

[[ 2.     -9.      5.     -4.    ]
 [ 1.2    -5.3999  6.      0.6001]
 [ 1.     -1.     -7.5    -8.5   ]]
ответ :
0.000000
1.000000
1.000000