Question

Write an expression to describe the sequence below. Use n to represent the position of a term in the sequence, where n = 1 for the first term. -68, -136, -204, -272, ... Questions

Answer 1

Each term differs by -68 and the first term is -68, we have:

$a_{n}=a_1-68(n-1) \implies \\ a_{n}=a_1-68n+68 \implies\\ a_n=-68-68n+68 \implies \\ a_n=-68n$

As an expession it's just -68n.