text: #invertMatrix.py
  import numpy as np
  # create vertical array
  x1 = np.array([1,2,1])
  x2 = np.array([4,1,5])
  x3 = np.array([6,8,6])
  print("Array 1:",x1, sep="\n")
  print("Array 2:",x2, sep="\n")
  print("Array 3:",x3, sep="\n")
  
  x1 = np.matrix(x1)
  x2 = np.matrix(x2)
  x3 = np.matrix(x3)
  print("Row Vector 1:",x1, sep="\n")
  print("Row Vector 2:",x2, sep="\n")
  print("Row Vector 3:",x3, sep="\n")
  
  X = np.concatenate((x1,x2,x3), axis=0)
  X_inverse = np.round(X.getI(), 2)
  print("X:", X, sep="\n")
  print("X Inverse:", X_inverse, sep="\n")