Restate the absolute value constraint as a combination of two linear constraints: I know how to find the optimal solution (std form, canonical form, simplex algorithm ...etc) I don't know how to put the absolute value constraint as a combo of 2 linear constraints. What are the procedures?
Example maximize $z=60x_1+20x_2$ such that (constraints): $x_1+x_2 <= 5$ and $|x_1-x_2| <= 2$ where $x_1$ and $x_2$ are both $\ge 0$.
$|x_{1} - x_{2}| \leqslant 2$ holds if $ x_{1} - x_{2} \leqslant 2$ and $x_{1} - x_{2} \geqslant -2$.