Ted practices two types of swimming styles for a total of 50 minutes every day. he spends 20 minutes more practicing the breast stroke than the butterfly stroke.

part a: write a pair of linear equations to show the relationship between the number of minutes ted practices the butterfly stroke every day (x) and the number of minutes he practices the breast stroke every day (y).
part b: how much time does ted spend on practicing the breast stroke every day?
part c: is it possible for ted to have spent 45 minutes practicing the butterfly stroke every day?