Q: How can I delete photos from my ipad that I put on through a cable connection?

Hi,

I'm a new ipad user and have just successfully set up iCloud on my PC and ipad.  Before I did this, I put photos on my ipad using the cable connection from the PC and drag and drop.  These photos don't appear in Photostream and I can't manage to delete them, or the Album I created for them.  One can only delete from Photostream I think.  I can't move them to Photostream, and I can't delete the Album, either.  How can I get rid of them?