Question

What is a40 for the arithmetic sequence presented in the table below?

Table:
n 8 12
an 60 48

Hint: an = a1 + d(n − 1), where a1 is the first term and d is the common difference.

Please help me. I just started learning this concept in an online math class and I keep watching the videos and looking over my notes and cannot figure out this problem. I semi-understand what the formula is, and I pretty much know how to plug in the values and what letter means what, just not for this problem apparently.

Answer 1

I did this question previously, and I'm pretty confident with my answer.

At the local grocery store, cans of beans are arranged in rows. The number of cans in each row forms an arithmetic sequence. There are 93 cans in row 1, 88 cans in row 2, 83 cans in row 3, and so on. One row contains 48 cans. Which row is this?

Row 7
Row 8
Row 9
Row 10 ***

for the equation, I did a1=93, d=-5, an=48, and solved for n. So I know what I'm doing, just not for the question I posted.