Write a general term that models this arithmetic sequence

Question

Write a formula that models the general term of the following arithmetic progression:

Chairs are being collected in the cafeteria. Each student gets a cart on which the student brings 8 chairs (from outside) into the cafeteria. After the first student leaves the cafeteria, the cafeteria now has 36 chairs in the room.

Answer 1

Hi Lyuda,

After one student came in the cafe and deposited 8 chairs, there were 36 chairs. That means that there were 28 chairs before any students brought chairs. In a table:

Student deliveries Chairs

0 28

1 36

2 44

So, starting amount 28, increasing by 8 with each student.

a_n = 8n + 28

Enjoy