Saying no to student requests for excessive appointments and help solving homework I am relatively new to teaching University undergraduate classes in mathematics. One of the harder things I've had to do is to say 'no'. To somehow respectfully deny a student what they're asking for. 

For example, very recently, a student has been demanding too many appointments outside of office hours and during these appointments, the student asks me to solve various questions for them and also almost entirely help them on their homework. As their instructor, I am certain that the student isn't actually understanding anything, but is rather making me do their homework. 

My question is, how do I tell them that their homework is not meant for me? Another question I have is, I feel like making compromises on my research time and family life to spend doing a student's homework doesn't seem like the best use of my time. So am I required to meet them outside of office hours? Or is it frowned upon if an instructor says no to meet outside of office hours?
I would limit the amount of time you dedicate to a single student to a maximum of 20 minutes a week. This is a reasonable amount of time to discuss the main problems a student has. This does not mean that you cannot make exceptions, but it is good to have a general rule.

As a side remark: You will not make everybody happy. If somebody wants an appointment and you say "no", and he insists, you can still say "no" and walk away.