If $A = \left[ \begin{array} { l l } 4 & 6 \\1 & 2\end{array} \right]$

Essay

If $A = \left[ \begin{array} { l l } 4 & 6 \\1 & 2\end{array} \right]$ , and $B = \left[ \begin{array} { c c } - 1 & 4 \\5 & - 2\end{array} \right]$ then find $A - 2 B$ .