Question:
If $A=\left(\begin{array}{ll}2 & 5 \\ 1 & 3\end{array}\right)$ then adj $A=$ ?
A. $\left(\begin{array}{cc}3 & -5 \\ -1 & 2\end{array}\right)$
B. $\left(\begin{array}{cc}3 & -1 \\ -5 & 2\end{array}\right)$
c. $\left(\begin{array}{cc}-1 & 2 \\ 3 & -5\end{array}\right)$
D.None of these
Solution: