Unable to delete Photos from my iPad Air

If you are attempting to fully reset the iPad - erasing all locally stored photos and data - the iPad can be reset from settings:

Settings > General > Transfer or Reset iPad > Erase All Content & Settings

After your iPad restarts, you can set-up from the initial "hello" screen. During setup, keep the iPad away from other devices - as otherwise you may trigger the QuickStart process that will automatically transfer data and settings from another device is close proximity. Skip any steps that offer to restore from iCloud or an iTunes backup.

As described, your photos on your iPad (and Mac computer) are likely synchronised to your iCloud Photo Library. Every time you reset your iPad, Photos within the iCloud Library will again synchronise with your iPad.

If using iCloud to synchronise photos or files between devices, be aware that successful deletion from one device will result in the deletion being replicated via iCloud to any other devices that are signed-in to iCloud with the same AppleID.

Synchronisation with iCloud is enabled/disabled from settings:

Settings > [Your Name / AppleID] > iCloud > Photos

What is happening if you press hold one photo, and see the menu. Is there a delete option there ?>