Determinant of $$$\left[\begin{array}{cc}17 - \lambda & 3\\3 & 9 - \lambda\end{array}\right]$$$

Calculate $$$\left|\begin{array}{cc}17 - \lambda & 3\\3 & 9 - \lambda\end{array}\right|$$$.

The determinant of a 2x2 matrix is $$$\left|\begin{array}{cc}a & b\\c & d\end{array}\right| = a d - b c$$$.

$$$\left|\begin{array}{cc}17 - \lambda & 3\\3 & 9 - \lambda\end{array}\right| = \left(17 - \lambda\right)\cdot \left(9 - \lambda\right) - \left(3\right)\cdot \left(3\right) = \lambda^{2} - 26 \lambda + 144$$$

$$$\left|\begin{array}{cc}17 - \lambda & 3\\3 & 9 - \lambda\end{array}\right| = \left(\lambda - 18\right) \left(\lambda - 8\right)$$$A