Solution LC.C40 Robert Beezer
Row-reduce the augmented matrix representing this system, to find \begin{equation*} \begin{bmatrix} \leading{1} & -2 & 0 & 6 & 0 & 1\\ 0 & 0 & \leading{1} & -4 & 0 & 3\\ 0 & 0 & 0 & 0 & \leading{1} & -5\\ 0 & 0 & 0 & 0 & 0 & 0 \end{bmatrix} \end{equation*} The system is consistent (no pivot column in column 6, Theorem RCLS). $x_2$ and $x_4$ are the free variables. Now apply Theorem VFSLS directly, or follow the three-step process of Example VFS, Example VFSAD, Example VFSAI, or Example VFSAL to obtain \begin{equation*} \colvector{x_1\\x_2\\x_3\\x_4\\x_5} = \colvector{1\\0\\3\\0\\-5}+ x_2\colvector{2\\1\\0\\0\\0}+ x_4\colvector{-6\\0\\4\\1\\0} \end{equation*}