Evaluate : if possible :

$\begin{bmatrix$}[r] 1 & -2 \ \end{bmatrix}\begin{bmatrix}[r] -2 & 3 \ -1 & 4 \end{bmatrix}

Evaluate : if possible :

$\begin{bmatrix$}[r] 6 & 4 \ 3 & -1 \end{bmatrix}\begin{bmatrix}[r] -1 \ 3 \end{bmatrix}

If A = $\begin{bmatrix$}[r] 0 & 2 \ 5 & -2 \end{bmatrix}, B = \begin{bmatrix}[r] 1 & -1 \ 3 & 2 \end{bmatrix} and I is a unit matrix of order 2 × 2, find :

(i) AB

(ii) BA

(iii) AI

If A = $\begin{bmatrix$}[r] 3 & x \ 0 & 1 \end{bmatrix} \text{ and B} = \begin{bmatrix}[r] 9 & 16 \ 0 & -y \end{bmatrix}, find x and y when A² = B.