Chapter 9, Problem 21RE

To determine

To calculate: The value of $AB$ where, the matrices are, $A=\left[\begin{array}{lll}2\hfill & -1\hfill & 2\hfill \\ 5\hfill & 3\hfill & -1\hfill \end{array}\right],B=\left[\begin{array}{ll}0\hfill & -2\hfill \\ 3\hfill & 2\hfill \\ 1\hfill & -5\hfill \end{array}\right],C=\left[\begin{array}{ccc}1& 2& 3\\ -1& 1& 2\\ -1& 2& 1\end{array}\right]$ and $D=\left[\begin{array}{lll}-2\hfill & 3\hfill & 1\hfill \\ 3\hfill & -2\hfill & 4\hfill \end{array}\right]$.