deletions | additions       diff --git a/begin_equation_left_begin_matrix__.tex b/begin_equation_left_begin_matrix__.tex  index 647afd1..da7aea6 100644  --- a/begin_equation_left_begin_matrix__.tex  +++ b/begin_equation_left_begin_matrix__.tex 
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\begin{equation}  \left\\  \begin{matrix} \begin{cases}  x_{k+1} = a\cdot x_{k}+k\cdot sin(k) + \xi_{k} \\ y_{k} = b\cdot x_{k}+\eta_{k} \right  \end{matrix}\tag{2} \end{cases}\tag{2}  \end{equation}