Is this the appropriate place to post on the topic? I couldn't find anywhere else so I chose here. Can anyone offer some advice on the linear programs of these 3 problems? I don't need help putting them into the program LINGO to solve them though. If I can understand how to do these kinds of problems my teacher says similar style questions will be in the test, so I really need to understand the method. Thanks for your time everyone.

See the attached imageOperations Research (Operations Management)-objective-functions.png