$A=\left[\begin{array}{rr}12 & 14 & -3 & 6
\\2 & 18 & -10 &12
\\1 &-9 &40 & -2
\\3 &3 &6 & 1\end{array}\right]$
**$A_{2,4}=$** [[☃ math-keypad 1]]
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