0003.tex

\begin{exercise}{M1}{Multiplying matrices}{0003}
\begin{exerciseStatement}

Of the following three matrices, only two may be multiplied. \[
          A= \left[\begin{array}{cccc}
1 & -3 & 4 & 6 \\
0 & 1 & -2 & -1
\end{array}\right]  \hspace{1em} B= \left[\begin{array}{ccc}
1 & 5 & 6 \\
0 & 0 & 1
\end{array}\right]  \hspace{1em} C= \left[\begin{array}{ccc}
1 & -1 & -5 \\
0 & 1 & 3 \\
1 & -1 & -4 \\
0 & 0 & 2
\end{array}\right] \] Explain which two can be multiplied and why. Then show how to find their product.

\end{exerciseStatement}
\begin{exerciseAnswer}\[AC= \left[\begin{array}{ccc}
5 & -8 & -18 \\
-2 & 3 & 9
\end{array}\right] \]\end{exerciseAnswer}
\end{exercise}