Let u_1, u_2, v_1,and v_2 be vectors in real matrix 1xn where v_1,and v_2 are linearly independent. Let A=(tranpose u_1) v_1 + (tranpose u_2) v_2.

prove that the column space of A is equal to <(tranpose u_1), (tranpose u_2)> or span by {(tranpose u_1), (tranpose u_2)}.