how do I delete photos that were synced to my iPhone 5c by Mac

Hi

How photos are managed depends on the services that you are using.

If you are using iCloud Photo Library, then deleting a photo or video on any one device that is using this service will delete that item across all of them and within iCloud.

The following resources may prove helpful in explaining some of various available services and actions for managing photos and videos:

If you are syncing photos manually via iTunes (see under "Turn off iTunes syncing"):

• Keep your photos safely stored and up to date on all your devices - Apple Support

iCloud Photo Library

• iCloud Photo Library - Apple Support
• Get help with your iCloud Photo Library - Apple Support

iCloud Photo Sharing

• Get help using iCloud Photo Sharing and shared albums - Apple Support

My Photo Stream

• iCloud: My Photo Stream overview
• My Photo Stream FAQ - Apple Support