If $A=\begin{bmatrix}1&2&2 \\ 2&1&2\\2&2&1\end{bmatrix}$ then what is $A{}^2-4A$ equal to?

If $A=\begin{bmatrix}x&y&z\\y&z&x\\z&x&y\end{bmatrix}$

where x,y,z are integers, is an orthogonal matrix, then what is A² equal to?

Let X be a matrix of order 3 x 3, Y be a matrix of order 2 x 3 and Z be a matrix of order 3 × 2. Which of the following statements are correct?

I. (ZY)X is defined and is a square matrix of order 3.

II. Y(XZ) is defined and is a square matrix of order 2.

III. X(YZ) is not defined.

Select the answer using the code given below.

Let A and B be two square matrices of same order. If AB is a null matrix, then which one of the following is correct?