0009.tex

\begin{exercise}{M1}{Multiplying matrices}{0009}
\begin{exerciseStatement}

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

\end{exerciseStatement}
\begin{exerciseAnswer}\[CB= \left[\begin{array}{ccc}
7 & 31 & 14 \\
1 & 4 & 2 \\
-4 & -19 & -8 \\
-10 & -44 & -20
\end{array}\right] \]\end{exerciseAnswer}
\end{exercise}