\begin{array}{*{20}c}
 {1.} \\
 {2.} \\
 {3.} \\
 {4.} \\
 {5.} \\

 \end{array} \left[ {\begin{array}{*{20}c}
 1 & 2 & 1 & 1 \\
 1 & 0 & 0 & 0 \\
 0 & 1 & 0 & 0 \\
 0 & 0 & 1 & 0 \\
 0 & 0 & 0 & 1 \\

 \end{array} } \right] \sim \begin{array}{*{20}c}
 {1.} \\
 {2.} \\
 {3.} \\
 {4.} \\
 {5.} \\

 \end{array} \left[ {\begin{array}{*{20}c}
 1 & 0 & 0 & 0 \\
 1 & 0 & 0 & 0 \\
 0 & 1 & 0 & 0 \\
 0 & 0 & 1 & 0 \\
 0 & 0 & 0 & 1 \\

 \end{array} } \right]