If $x=\left[ \begin{matrix} 1 & 0 & 1 \\ 2 & -1 & 0 \\ -1 & 0 & 1 \\\end{matrix} \right]$ and $y=\left[ \begin{matrix} -1 & 1 & 2 \\ 0 & -1 & -1 \\ 2 & -1 & -1 \\\end{matrix} \right]$find 2x – y
$\begin{align} & 2x-y=2\left[ \begin{matrix} 1 & 0 & 1 \\ 2 & -1 & 0 \\ -1 & 0 & 1 \\\end{matrix} \right]-\left[ \begin{matrix} -1 & 1 & 2 \\ 0 & -1 & -1 \\ 2 & -1 & 1 \\\end{matrix} \right] \\ & =\left[ \begin{matrix} 2 & 0 & 2 \\ 4 & -2 & 0 \\ -2 & 0 & 2 \\\end{matrix} \right]-\left[ \begin{matrix} -1 & 1 & 2 \\ 0 & -1 & -1 \\ 2 & -1 & 1 \\\end{matrix} \right] \\ & =\left[ \begin{matrix} 2-(-1) & 0-1 & 2-2 \\ 4-0 & -2-(-1) & 0-(-1) \\ -2-2 & 0-(-1) & 2-1 \\\end{matrix} \right] \\ & =\left[ \begin{matrix} 3 & -1 & 0 \\ 4 & -1 & 1 \\ -4 & 1 & 1 \\\end{matrix} \right] \end{align}$