b)
$$ \begin{pmatrix} x_{11} & x_{12} \\ x_{21} & x_{22}\end{pmatrix} *\begin{pmatrix} 0 & 1 \\ 1 & 0 \end{pmatrix} =\begin{pmatrix} x_{12} & x_{11} \\ x_{22} & x_{21}\end{pmatrix} $$$$x_1= \begin{pmatrix} x_{11} \\ x_{21}\end{pmatrix} ; x_2= \begin{pmatrix} x_{12} \\ x_{22}\end{pmatrix} $$
c)
$$ \begin{pmatrix} x_{11} & x_{12}&x_{13} \\x_{21}&x_{22}&x_{23}\\x_{31}&x_{32}&x_{33}\end{pmatrix} * \begin{pmatrix} 1 \\ 1\\1\end{pmatrix} = \begin{pmatrix} x_{11} + x_{12}+x_{13} \\x_{21}+x_{22}+x_{23}\\x_{31}+x_{32}+x_{33}\end{pmatrix} $$
d)$$ \begin{pmatrix} x_{11} & x_{12} \\ x_{21} & x_{22}\end{pmatrix} *\begin{pmatrix} 1 & 1 \\ 1 & -1 \end{pmatrix} =\begin{pmatrix} x_{11} + x_{12}&x_{11}-x_{12} \\x_{21}+ x_{22} & x_{21}-x_{22}\end{pmatrix} $$