Q: delete photos that do not have a wastebasket

How did they get onto the iPad, what album are they in (Camera Roll, or a synced album) ? If they were synced from a computer then they can't be deleted directly in the Photos app, they are deleted by reconnecting to your computer's iTunes and changing your photo sync selection.

What album are they in on the iPad, Camera Roll, My Photo Stream or something else ?

You are using iCloud Photo Library (Settings > iCloud > Photos ; you don't have a Camera Roll album in the Photos app) ? I'm not using it, but I thought that you could delete photos from it in the Photos app (Get help with your iCloud Photo Library - Apple Support). Or aren't you using iCloud Photo Library on the iPad and still have a Camera Roll album ?

If you have Camera Roll then that implies to me (based on what I've read about iCloud Photos, if somebody who is using it knows different hopefully they'll reply) that they were synced from a computer - you have Settings > iCloud > Photos > iCloud Photo Library 'off' ?

If you do then have you tried selecting and syncing an empty photo on the Photos tab when connected to your computer's iTunes to see if that removes that album ?