Question

Find an equation for the nth term of the arithmetic sequence. -17, -13, -9, -5, ...

Answer 1

The nth term is
`a_n=4n-21`

Explanation:

The given arithmetic sequence is -17, -13, -9, -5, ...

The first term of this sequence is
`a_1=-17`.

The common difference can be found using any two consecutive terms.

The common difference is
`d=-5--9=4`

The nth term of arithmetic sequence is given by the formula:

`a_n=a_1+d(n-1)`

We plug in the values to obtain:

`a_n=-17+4(n-1)`

Expand

`a_n=-17+4n-4`

Simplify:

`a_n=4n-21`