Use the simplex method to maximize LaTeX:  \displaystyle p = 3 x + 13 y subject to LaTeX:  \displaystyle \begin{cases}61 x + 41 y \leq 2501 \\ 2 x + 79 y \leq 158 \\x \geq 0, y \geq 0 \end{cases}

Adding the slack variables LaTeX:  \displaystyle s and LaTeX:  \displaystyle t to the inequalities gives:
LaTeX:  \begin{cases}61 x + 41 y +s = 2501 \\ 2 x + 79 y+t = 158 \\ - 3 x - 13 y+p =0 \end{cases} This gives the first tableau:\begin{tabular}{|c|c|c|c|c|c|c|}\hline LaTeX:  \displaystyle  & LaTeX:  \displaystyle x & LaTeX:  \displaystyle y & LaTeX:  \displaystyle s & LaTeX:  \displaystyle t & LaTeX:  \displaystyle p & LaTeX:  \displaystyle  \\ \hline LaTeX:  \displaystyle s & LaTeX:  \displaystyle 61 & LaTeX:  \displaystyle 41 & LaTeX:  \displaystyle 1 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 2501 \\ \hline LaTeX:  \displaystyle t & LaTeX:  \displaystyle 2 & LaTeX:  \displaystyle 79 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 1 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 158 \\ \hline LaTeX:  \displaystyle p & LaTeX:  \displaystyle -3 & LaTeX:  \displaystyle -13 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 1 & LaTeX:  \displaystyle 0 \\ \hline \end{tabular}
The pivot row is LaTeX:  \displaystyle t and the pivot column is LaTeX:  \displaystyle y . The departing variable is LaTeX:  \displaystyle t and the incoming variable is LaTeX:  \displaystyle y . Pivoting using the row operations:
LaTeX:  \displaystyle 79R_1-41R_2
LaTeX:  \displaystyle 79R_3+13R_2
\begin{tabular}{|c|c|c|c|c|c|c|}\hline LaTeX:  \displaystyle  & LaTeX:  \displaystyle x & LaTeX:  \displaystyle y & LaTeX:  \displaystyle s & LaTeX:  \displaystyle t & LaTeX:  \displaystyle p & LaTeX:  \displaystyle  \\ \hline LaTeX:  \displaystyle s & LaTeX:  \displaystyle 4737 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 79 & LaTeX:  \displaystyle -41 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 191101 \\ \hline LaTeX:  \displaystyle y & LaTeX:  \displaystyle 2 & LaTeX:  \displaystyle 79 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 1 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 158 \\ \hline LaTeX:  \displaystyle p & LaTeX:  \displaystyle -211 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 13 & LaTeX:  \displaystyle 79 & LaTeX:  \displaystyle 2054 \\ \hline \end{tabular}
The pivot row is LaTeX:  \displaystyle s and the pivot column is LaTeX:  \displaystyle x . The departing variable is LaTeX:  \displaystyle s and the incoming variable is LaTeX:  \displaystyle x . Pivoting using the row operations:
LaTeX:  \displaystyle 4737R_2-2R_1
LaTeX:  \displaystyle 4737R_3+211R_1
\begin{tabular}{|c|c|c|c|c|c|c|}\hline LaTeX:  \displaystyle  & LaTeX:  \displaystyle x & LaTeX:  \displaystyle y & LaTeX:  \displaystyle s & LaTeX:  \displaystyle t & LaTeX:  \displaystyle p & LaTeX:  \displaystyle  \\ \hline LaTeX:  \displaystyle x & LaTeX:  \displaystyle 4737 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 79 & LaTeX:  \displaystyle -41 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 191101 \\ \hline LaTeX:  \displaystyle y & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 374223 & LaTeX:  \displaystyle -158 & LaTeX:  \displaystyle 4819 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 366244 \\ \hline LaTeX:  \displaystyle p & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 16669 & LaTeX:  \displaystyle 52930 & LaTeX:  \displaystyle 374223 & LaTeX:  \displaystyle 50052109 \\ \hline \end{tabular}
There are no negative values in row LaTeX:  \displaystyle p and this is the final tableau.The value of LaTeX:  \displaystyle x is LaTeX:  \displaystyle \frac{191101}{4737} . The value of LaTeX:  \displaystyle y is LaTeX:  \displaystyle \frac{4636}{4737} . The max value is LaTeX:  \displaystyle p = \frac{633571}{4737}