HELP PLZ I'M IN A TIME LIMITED TEST 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. and 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 is THE PART I NEED!!!