This is LaTeX code:

[latex]
A_1= \left[ {\begin{array}{*{20}c} 1 & 2 \\ { 0} & { 1} \\ \end{array}} \right],A_2=\left[ {\begin{array}{*{20}c} 0 & 0 \\ { -1} & { 1} \\ \end{array}} \right], A_3= \left[ {\begin{array}{*{20}c} 0 & 2 \\ { 1} & { 1} \\ \end{array}} \right]
[/latex]