I moved the files from my internal storage to SD, which created 4 andriod folders. Each of them are 10 GB, which uses up a lot of space. Is it safe to delete them?
If the same files are in each one, probably. But I'd copy them to a PC, one at a time, labeling them Android1, Android2 and Android 3, then delete those 3. Then if you're missing a file in the one left, it's in one of the folders you backed up.