Sorry if I just overlooking something, but I don't see how to merge two questions in one.
I asked question Can be profitable to migrate from Windows to Linux in a small business? which was by opinion of others confusing. In order to improve my question I re-ask it as was suggested in comments. Thus I created another question What factors contribute to the expense of migrating to Linux? and intended to delete the old one. Then the new one was marked as a duplicate (of course it is, because is improvement of the old poorly asked question).
In the commentary to duplicate closure is written answers may be merged with another identical question. How do I do that?