Chapter 9, Problem 31RE

For Exercises 31-40, perform the indicated operations if possible.

$A=\left[\begin{array}{rr}\hfill -4& \hfill 1\\ \hfill 6& \hfill -2\\ \hfill 1& \hfill 3\end{array}\right]$ $B=\left[\begin{array}{rrr}\hfill 2& \hfill 3& \hfill -7\\ \hfill 1& \hfill 5& \hfill -6\end{array}\right]$ $C=\left[\begin{array}{rr}\hfill \pi & \hfill 4\\ \hfill -3& \hfill 1\\ \hfill 0& \hfill 5\end{array}\right]$

$3A$