three use cases into one use case

Question

I have one actor (admin), he can perform some actions over other user accounts such as creating the account, editing the account and deleting the account account. Should I do so

Answer 1

I think that in the diagram, the Admin actor should interact with the specialized (child) use cases rather than the more abstract (parent) use case.

Furthermore, it is a good practice to show the system boundary using a frame around all the use cases implemented by your system. This is especially helpful when you have more than one external actor.

This page is also helpful for understanding the concept of generalization.