def test_LU():
A = DenseMatrix(3, 3, [1, 3, 5, 2, 5, 6, 8, 3, 1])
L, U = A.LU()
assert L == DenseMatrix(3, 3, [1, 0, 0, 2, 1, 0, 8, 21, 1])
assert U == DenseMatrix(3, 3, [1, 3, 5, 0, -1, -4, 0, 0, 45])
def test_LU():
A = DenseMatrix(3, 3, [1, 3, 5, 2, 5, 6, 8, 3, 1])
L, U = A.LU()
assert L == DenseMatrix(3, 3, [1, 0, 0, 2, 1, 0, 8, 21, 1])
assert U == DenseMatrix(3, 3, [1, 3, 5, 0, -1, -4, 0, 0, 45])