ABSTRACT
Equations are easier to deal with than inequalities. In linear programming problems, we can replace an inequality
a
x
+
a
x
+
…
+
a
x
£
b
by the equivalent equality
a
x
+
a
x
+
…
+
a
x
+
r
=
b
where
r
is a new variable. The equivalence depends on the fact that, in linear programming problems, variables are assumed to take only non-negative values. The new variable
r
is called a
slack variable
.
