evaluate the unit worth and feasibility range for both binding resources please!!

A company manufactures two types of steel at three different steel mills. During a given month, each steel mill has 400 hours of blast furnace time available. Because of differences in the furnaces at each mill, the time and cost to produce a ton of steel differ for each mill. The time and cost for each mill are shown in the table below. Each month, the company must manufacture at least 500 tons of steel 1 and 600 tons of steel 2. Formulate an LP model to minimize the cost of manufacturing the required steel. Mill 1 2. Cost $10 S12 $14 Steel 1 Time (Minutes) 20 24 28 Cost $11 S9 $10 Steel 2 Time (Minutes) 22 18 30