THIS IS MY 4TH TIME POSTING THIS (I did it on my other account )Abby has just started training for a marathon. She ran 15 miles in total during her first week of training. She wants to add an additional 2 miles to her weekly total during each subsequent week. Write an explicit rule for the arithmetic sequence that represents this situation, and use it to find how many miles Abby will run during her twelfth week of training. Please show work for full credit