Question

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

Find the common difference.
Im just confused.
How do I do this?
A(13)=-5+10(1)(18)

Answer 1

The nth term of any arithmetic sequence is given by this formula...
\[\Large a_n = a_1 + (n-1)d\]
Just have n = 10
and you know that \(\Large a_{10} = 13\)

Answer 2

Oh, and \(\Large a_1\) is the first term.

Answer 3

yeah,So would the correct way instead be. A(10)=-5+(10-1)(18)?