Chapter 6.2, Problem 7E

In Problems 5-8, find the pivot element, identify the entering and exiting variables, and perform one pivot operation.

$\begin{array}{l}{x}_1{x}_2{s}_1{s}_2{s}_{3}P\\ \left[\begin{array}{ccccccc}2& 1& 1& 0& 0& 0& 4\\ 3& 0& 1& 1& 0& 0& 8\\ 0& 0& 2& 0& 1& 0& 2\\ -4& 0& -3& 0& 0& 1& 5\end{array}\right]\end{array}$