Separate combined jpeg and RAW files
I recently decided to use Photos and iCloud to manage and store my photos instead of DropBox. After importing all of my photos into Photos, I have some pairs of RAW and jpegs that appear as separate files and some that appear to be combined into a single file with a J or an R in the upper right hand corner. What I would like to know I can separate the combined files, especially if I want to delete one and keep the other, plus how to combine the separated ones.
Mac mini, macOS High Sierra (10.13.2)