.
See THIS Wikipedia article
https://en.wikipedia.org/wiki/Feasible_region
In mathematical optimization, a feasible region, feasible set, search space, or solution space is the set of all possible points
(sets of values of the choice variables) of an optimization problem that satisfy the problem's constraints, potentially including
inequalities, equalities, and integer constraints.
This is the initial set of candidate solutions to the problem, before the set of candidates has been narrowed down.
To see on how this notion/conception works, and also to see on how the linear programming method works for such problems, look into the lesson
- Solving minimax problems by the Linear Programming method
in this site.