Hi, I'm Robert and I'll be helping you with your computer question.
You don't really have to delete either of them.
You can just let them sit there and they will eventually close themselves due to lack of use.
unfortunately deleting an account requires that you prove ownership. If you could do that you would not need to delete them because you could have just kept using them.
The facebook account you might be able to get rid of by flagging it as identity theft. In that case they would send an email to the registered email on the account asking them to prove that they are the person in the account. When nobody answered them because nobody can get into the email account they will close the account.
But it doesnt really seem worth the bother. I know many people that have multiple facebook accounts and even more people that have an old one floating around that they don't remember and can't get into.