In [1]:
import numpy as np
import matplotlib.pyplot as plt

%matplotlib inline
In [2]:
a = np.array([[3,-5,4],[1,-2,7],[6,-8,1]])
b = np.array([[7],[2],[0]])
In [3]:
x = np.linalg.solve(a, b)
print(x)

[[-12.        ]
 [ -9.07407407]
 [ -0.59259259]]