>>> x = np.matrix(((2, 3), (3, 5)))
>>> x
matrix([[2, 3],
        [3, 5]])
>>> y = np.matrix(((1, 2), (5, -1)))
>>> y
matrix([[ 1,  2],
        [ 5, -1]])
>>> z = x * y
>>> z
matrix([[17,  1],
        [28,  1]])