Question

If $A = \begin{bmatrix} 1 & 2 & 2 \\\ 2 & 1 & 2 \\\ 2 & 2 & 1 \end{bmatrix}$and I = unit matrix, then the value of $A^2-4A$ is:

• A. 3I
• B. 4I
• C. 5I
• D. 6I

Answer 1

Answer: (C)

5I

Answer 2

The correct option is (C): 5I