Chapter 4.1, Problem 1E

Solve the normal equations to find the least squares solution and 2-norm error for the following inconsistent systems:

$\text{a}.\left[\begin{array}{l}\begin{array}{cc}1& 2\end{array}\\ \begin{array}{cc}0& 1\end{array}\\ \begin{array}{cc}2& 1\end{array}\end{array}\right]\left[\begin{array}{c}{x}_1\\ x_2\end{array}\right]=\left[\begin{array}{c}3\\ 1\\ 1\end{array}\right]$ $\text{b}.\left[\begin{array}{l}\begin{array}{cc}1& 1\end{array}\\ \begin{array}{cc}2& 1\end{array}\\ \begin{array}{cc}3& 1\end{array}\end{array}\right]\left[\begin{array}{c}{x}_1\\ x_2\end{array}\right]=\left[\begin{array}{c}1\\ 2\\ 0\end{array}\right]$ $\text{c}.\left[\begin{array}{l}\begin{array}{cc}1& 2\end{array}\\ \begin{array}{cc}1& 1\end{array}\\ \begin{array}{cc}2& 1\end{array}\\ \begin{array}{cc}2& 2\end{array}\end{array}\right]\left[\begin{array}{c}{x}_1\\ x_2\end{array}\right]=\left[\begin{array}{c}3\\ 3\\ 3\\ 2\end{array}\right]$