Determine a direct complement of the linear subspace U ⊆ R 3 {\displaystyle {}U\subseteq \mathbb {R} ^{3}} generated by ( − 5 4 9 ) {\displaystyle {}{\begin{pmatrix}-5\\4\\9\end{pmatrix}}} and ( 2 − 7 3 ) {\displaystyle {}{\begin{pmatrix}2\\-7\\3\end{pmatrix}}}
