Question 851700
The number of seats in the first 12 rows of a high school  auditorium from an arithmetic sequence. The first row has 9 seats. The second row has 11 seats.
Show all work.
a) Write a recursive formula to represent the sequence.
b) Write an explicit formula to represent the sequence.
c) How many seats are in the 12th row?
an = a1 + (n - 1)d
a12 = 9 + 2(11)
a12=31 seats in the 12th row
an = 9 + 2(n - 1)
An=9+2n-2
An=2n+7 explicit 

an = a(n-1) + 2 recursive