Idon't know the rest or don't know if i'm doing it correctly

Identify a1 and r for the geometric sequence an= -256(-1/4) n-1

Ineed with the quizzes in apex mathematics ii

Sherrie is baking a pie for her family. she leaves the room and comes back to 35% of the pie having been eaten before she can put the topping on. how much 1 square inch strips of dough will she need for the top, now that a portion is missing? round your answer to the nearest while nimber.