Question

The value of $|Adj.B|$ is equal to where

$B=\left(\begin{array}{ccc}3& 2& 5\\ 2& 3& 8\\ 7& 2& 9\end{array}\right)$

• A. $24$
• B. ${\left(24\right)}^2$
• C. ${\left(24\right)}^3$
• D. ${\left(8\right)}^2$

Answer 1

The correct option is B ${\left(24\right)}^2$

$\left|B\right|=3(3\times 9-2\times 8)-2(2\times 9-7\times 8)+5(2\times 2-7\times 3)=24$

$\left|AdjB\right|={\left|B\right|}^{n-1}={24}^{3-1}={24}^2$
Ans: B