Given $A = \left[ \begin{array} { c c } 1 & 5 \\- 2 & 3\end{array} \right]$

Essay

Given $A = \left[ \begin{array} { c c } 1 & 5 \\- 2 & 3\end{array} \right]$
and $B = \left[ \begin{array} { c c c } 4 & 1 & - 1 \\3 & - 5 & 2\end{array} \right]$ , find $B A$ , or explain why the operation cannot be performed.