Please answer question A with step by step procedure

1. Company transport raw material from three different manufacturing plants to three warehouses. The supplies and demand requirements at the three plants and warehouses, and the transport cost per unit of raw material are as follows. Warehouses Z Supply Plants 1 1 9 100 2 9 1 9 90 3 5 4 7 80 125 60 70 Demand a. Solve the problem using the U-V method and the minimum costs method. b. Decide how the raw material should be transport with a minimum cost Z. c. In this problem what is the meaning of the dummy