Chapter 1.4, Problem 16E

Repeat Exercise 15: A = $\left[\begin{array}{ccc}1& -3& -4\\ -3& 2& 6\\ 5& -1& -8\end{array}\right]$, b = $\left[\begin{array}{c}{b}_1\\ b_2\\ b_3\end{array}\right]$.

15. Let A = $\left[\begin{array}{cc}2& -1\\ -6& 3\end{array}\right]$ and b = $\left[\begin{array}{c}{b}_1\\ b_2\end{array}\right]$. Show that the equation Ax = b does not have a solution for all possible b, and describe the set of all b for which Ax = b does have a solution.