$A=\left[\begin{array}{rr}12 & -12 & 8 & 3
\\-1 & 8 & -2 & 3
\\1 &0 &-9 & 15
\\16 &12 &8 & 5
\\10 &14 &3 & 19\end{array}\right]$
**$A_{4,1}=$** [[☃ math-keypad 1]]
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