Chapter 4.3, Problem 6CP

Use the MATLAB QR factorization to find the least squares solutions and 2-norm error of the following inconsistent systems:

$\text{a}\text{. }\left[\begin{array}{l}\begin{array}{ccc}3& -1& 2\end{array}\\ \begin{array}{ccc}4& 1& 0\end{array}\\ \begin{array}{ccc}-3& 2& 1\end{array}\\ \begin{array}{ccc}1& 1& 5\end{array}\\ \begin{array}{ccc}-2& 0& 3\end{array}\end{array}\right]\left[\begin{array}{c}{x}_1\\ \begin{array}{l}{x}_2\\ x_3\end{array}\end{array}\right]=\left[\begin{array}{c}10\\ 10\\ -5\\ \begin{array}{l}15\\ 0\end{array}\end{array}\right]$ $\text{b}\text{. }\left[\begin{array}{l}\begin{array}{cccc}4& 2& 3& 0\end{array}\\ \begin{array}{cccc}-2& 3& -1& 1\end{array}\\ \begin{array}{cccc}1& 3& -4& 2\end{array}\\ \begin{array}{cccc}1& 0& 1& -1\end{array}\\ \begin{array}{cccc}3& 1& 3& -2\end{array}\end{array}\right]\left[\begin{array}{c}{x}_1\\ \begin{array}{l}{x}_2\\ x_3\\ x_4\end{array}\end{array}\right]=\left[\begin{array}{c}10\\ 0\\ 2\\ \begin{array}{l}0\\ 5\end{array}\end{array}\right]$