Question

The fifth term of an arithmetic sequence is 96. Which rule could define the sequence?

an = 5n + 96

an = 6n + 18

an = 18n + 6

an = 96n + 5

Answer 1

Compute a5 for each:

- a_n = 5n + 96 → a5 = 5·5 + 96 = 121
- a_n = 6n + 18 → a5 = 6·5 + 18 = 48
- a_n = 18n + 6 → a5 = 18·5 + 6 = 96 ✅
- a_n = 96n + 5 → a5 = 96·5 + 5 = 485

So the rule is a_n = 18n + 6.