import numpy as np

a = np.array([[2., 1.], [1., 1.]])
b = np.array([8., 5.])
x = np.linalg.solve(a, b)
print(np.allclose(x, [3., 2.], atol=1e-12))
print(np.allclose(a @ x, b, atol=1e-12))
singular = np.array([[1., 1.], [2., 2.]])
if np.linalg.matrix_rank(singular) < singular.shape[0]:
    print("Rejected singular system")
else:
    np.linalg.solve(singular, b)