Decide whether the linear system of equations \(A \vec{x} = \vec{b}\) has a solution. Then find a least squares solution. \[A = \begin{bmatrix} 1 & 2 \\ 0 & 4 \\ -2 & -1 \end{bmatrix}, \qquad \vec{b} = \begin{bmatrix} 1 \\ -1 \\ -3 \end{bmatrix}\]

Click for answer

Click for Latex code