Is the sequence {an} =[13, 20. 27, 34. ...] arithmetic? If so, identify the common difference. 0 A. yes,7 O B. yea7 O C. yes, 13 O D. no Write an explicit formula for the sequence {a, ) = (7,2, -3, -8, -13,...) . Then find a14 . O A. a =-5n+2, -58 O B. an = -5n+2, -68 O C. a =-5n+12; -68 O D. a, =-5n+12; -58Write a recursive formula for the sequence {a, } = {15, 26, 48, 92, 180, ...} . O A. a = 15, an = 2an -4 O B. a = 15, an = 2an-1 -4 O C. a = 15, a, = 4+11. 20-1 O D. a = 15, a, = 30,- -19Elia is training for her first marathon. She currently runs 10 mi. per week, and wants to increase her mileage by 2 mi. every week. If Elia keeps to her training schedule, write a formula to define the number of miles she runs each week. O A. a, = 2n+8 O B. a, =-2x +2 O C. a, = 2x +10 O D. a, =-2x+12