1.
Let B=(13α123αα4)B = \begin{pmatrix} 1 & 3 & \alpha \\ 1 & 2 & 3 \\ \alpha & \alpha & 4 \end{pmatrix}, with α>2\alpha > 2, be the adjoint of a 3×33\times 3 matrix AA and A=2|A| = 2. Then (α2αα2αααααα)B2αI\left|\begin{pmatrix} \alpha & -2\alpha & \alpha \\ -2\alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \end{pmatrix}\right| \cdot |B - 2\alpha\,I| is equal to:
Matrices and Determinants - Hard - Question