Question

Given a square matrix $A$ of order $3$, such that $\left|A\right|=5$, find $|\text{adj}A|$

Answer 1

$\begin{array}{c}Ifasquarematrixofordernthen,\\ \left|adjA\right|={\left|A\right|}^{n-1}\\ Here,\\ \left|A\right|=5\\ so,\\ \left|adjA\right|=5^{3-1}=5^2=25\end{array}$