Use the simplex method to maximize LaTeX:  \displaystyle p = 25 x + 21 y subject to LaTeX:  \displaystyle \begin{cases}79 x + 46 y \leq 3634 \\ 42 x + 94 y \leq 3948 \\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}79 x + 46 y +s = 3634 \\ 42 x + 94 y+t = 3948 \\ - 25 x - 21 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 79 & LaTeX:  \displaystyle 46 & LaTeX:  \displaystyle 1 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 3634 \\ \hline LaTeX:  \displaystyle t & LaTeX:  \displaystyle 42 & LaTeX:  \displaystyle 94 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 1 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 3948 \\ \hline LaTeX:  \displaystyle p & LaTeX:  \displaystyle -25 & LaTeX:  \displaystyle -21 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 1 & LaTeX:  \displaystyle 0 \\ \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 79R_2-42R_1
LaTeX:  \displaystyle 79R_3+25R_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 79 & LaTeX:  \displaystyle 46 & LaTeX:  \displaystyle 1 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 3634 \\ \hline LaTeX:  \displaystyle t & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 5494 & LaTeX:  \displaystyle -42 & LaTeX:  \displaystyle 79 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 159264 \\ \hline LaTeX:  \displaystyle p & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle -509 & LaTeX:  \displaystyle 25 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 79 & LaTeX:  \displaystyle 90850 \\ \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 2747R_1-23R_2
LaTeX:  \displaystyle 5494R_3+509R_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 x & LaTeX:  \displaystyle 217013 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 3713 & LaTeX:  \displaystyle -1817 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 6319526 \\ \hline LaTeX:  \displaystyle y & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 5494 & LaTeX:  \displaystyle -42 & LaTeX:  \displaystyle 79 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 159264 \\ \hline LaTeX:  \displaystyle p & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 0 & LaTeX:  \displaystyle 115972 & LaTeX:  \displaystyle 40211 & LaTeX:  \displaystyle 434026 & LaTeX:  \displaystyle 580195276 \\ \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{79994}{2747} . The value of LaTeX:  \displaystyle y is LaTeX:  \displaystyle \frac{79632}{2747} . The max value is LaTeX:  \displaystyle p = \frac{3672122}{2747}