Question

The first term of an arithmetic sequence is -5, and the tenth term is 13. Find the common difference.



8/9

1.8

2

Answer 1

Let's look at what the terms of an arithmetic sequence with first term \(a_1\) and common difference \(d\) look like:

\(a_1 = a_1\)
\(a_2 = a_1 + d\)
\(a_3 = a_1 + 2d\)
\(a _4 = a_1 + 3d\)
\(...\)
\(a_n = a_1 + (n - 1)d\)

You know \(a_n\), \(a_1\), and \(n\). Solve for \(d\).