Need help with linear Programming

Problem 10: (Difficulty level: 1) An accessory chain store company wants to position two warehouses between their stores and suppliers. There are two stores a, b located at (3, 9) and (6, 11) in the x-y plane, which must be reachable quickly and should therefore not be at a route of more than 5 km from each warehouse. The route between two warehouses also should be less than 2.5 km. The company has three suppliers m. n, o which operate for the following average number of days per month: 24, 28, and 20. These suppliers are located at the following positions in the x-y plane: (12; 3): (14, 7); and (21, 0). There is a river (generally following r(x) =-0.8x+14.4) across the stores and suppliers. It has to position one warehouse on the each side of the river and the warehouse only store the goods from suppliers located on the same side. The only bridge across the river is located at c (4, 11.2). The company wants to minimize the distance traveled between warehouses and suppliers in one month (assuming one tour per open day). (1) Derive the model of the optimisation problem: (2) solve the problem using three different methods/software and compare the obtained results; (3) formulate another two reasonable warehouse location design problems and solve them. 12 c(4, 1 2) b(6, 1 1) 10 (3, 9) (14,7) m(12.3) 0(21 0) 5 10 15 river 20 25 X