Before giving a more general algorithm for handling this problem and problems like it, we note that when the number of variables is small (preferably 2), a graphical technique can be used. Inequaliti...Before giving a more general algorithm for handling this problem and problems like it, we note that when the number of variables is small (preferably 2), a graphical technique can be used. Inequalities, such as the four given in Pablo's problem, are often called constraintsconstraints , and values of the variables that satisfy these constraints comprise the so-called feasible regionfeasible region .