Hi, I imported a picture taken in 2015 on my Samsung Galaxy Note 2 into my iPhone7+ when I got it in November 2017. Now I want to delete this pic. I can't. In my iPhone7+ I tap Photos, tap Photos, tap Select, tap the pic I want to delete and I get a check mark on the pic but . . . the trash icon in the bottom-right of the iPhone's screen remains greyed out. I've tried connecting my iPhone7+ to my Mac, opened iTunes, selected my iPhone7+ and . . . there's no Photo's folder under my iPhone7+ in iTunes. ARGGHH!!! What to do? Any help much appreciated!