If you do not retake the classes, the grades remain posted to your transcript, and they affect your GPA. This will influence admission to graduate school, if you ever decide to go. (It might not matter to employers, who sometimes do not look at transcript GPA information.) The smart thing to do is visit your academic adviser and get information from someone who knows what the result will be of any choice open to you. That person will tell you honestly if re-taking the courses will be worth your time, or whether it is smarter to let things stand as they are. You'll be getting information from an expert who knows your college rules, can look at your academic history, and has experience dealing with these matters.