marika is training for a track race She starts by sprinting 100 yards . She gradually increases her distance , adding 4 yards a day for 21 days how far does she sprint on day 21 using an=100+(n-1)4
For this case, you must use the given expression, taking into account that: n = number of days. We have then that for day 21, n = 21. Substituting we have: a21 = 100 + (21-1) * 4 a21 = 180 Answer: she sprints 180 yards on day 21
