Please show work step by step, and follow the instruction. Do not solve it in excel.

Given the costs, demands and supplies in the following table, use least-cost method to find an initial basic feasible solution and find the optimal transportation solution based on the initial basic feasible solution you found. Node 4 5 6 7 Supply 1 4 2 5 10 10 2 5 12 3 6 10 3 11 9 8 7 15 Demand 12 5 13 5 (Bonus 6 points: Do we have multiple optimal solutions? If so, provide at least one more optimal solution. If not, instead of 9, what is the new cost of 3-5 that can make this problem have multiple optimal solutions?) Requirements: You need to show the iterations of the algorithms (worth most of the points). Only showing an optimal solution will not be given full credits