| 0 1 |  | 1 5 |*
W = sp{ |     |, |     | }
        | 1 1 |  | 5 9 |

        | 1 2 |  | 1 -1|
U = sp{ |     |, |     | }
        | 4 1 |  | 3 2 |

find a base for U+W

*These are matrices, not determinants