Welcome to the forums. In Gallery, if you touch and hold a photo you should see the screen change and with a check in that particular photo and small circles in all the others. Once you touch a circle you'll see a checkmark there. If you then go to Delete (where varies with the app) and choose it that will delete those photos. HOWEVER, sometimes, instead of a direct delete, they may be placed in a trash folder for some period of time. Those may be what you are seeing. Otherwise, it sounds like you may be doing a copy instead of delete?
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