Formulate the mathematical optimization model for a RECTILINEAR MINSUM problem for a, b, and c (you do not have to solve the model but just mathematically formulate it).

a. The facility can be located anywhere

b. The facility must be at most 5.5 units from any resource

c. Including (b), the facility must be located at or to the right of an x coordinate equal to 5 AND above any y coordinate equal to 6.