<<< native
[ EArray
    [ AlignCenter ]
    [ [ [ EGrouped
            [ EGrouped
                [ EGrouped
                    [ ENumber "8.44" , ESymbol Ord "\8290" , EIdentifier "x" ]
                , ESymbol Bin "+"
                , EGrouped [ ENumber "55" , ESymbol Ord "\8290" , EIdentifier "y" ]
                ]
            , ESymbol Rel "="
            , ENumber "0"
            ]
        ]
      ]
    , [ [ EGrouped
            [ EGrouped
                [ EGrouped
                    [ ENumber "3.1" , ESymbol Ord "\8290" , EIdentifier "x" ]
                , ESymbol Bin "-"
                , EGrouped
                    [ ENumber "0.7" , ESymbol Ord "\8290" , EIdentifier "y" ]
                ]
            , ESymbol Rel "="
            , EGrouped [ ESymbol Bin "-" , ENumber "1.1" ]
            ]
        ]
      ]
    ]
]
>>> tex
\begin{matrix}
{{{8.44x} + {55y}} = 0} \\
{{{3.1x} - {0.7y}} = {- 1.1}}
\end{matrix}