Question

Find an equation for the nth term of the arithmetic sequence.

-13, -8, -3, 2, ...

an = -13 x 5(n - 1)
an = -13 + 5(n - 1)
an = -13 + 5(n + 2)
an = -13 + 5(n + 1)

Answer 1

The answer is the second answer choice, an = -13 + 5(n - 1)

Answer 2

Option B.

Explanation:

The given arithmetic sequence is

`-13,-8,-3,2,...`

We need to find the nth term of the given arithmetic sequence.

Here,

First term :
`a=-13`

Common difference :
`a_2-a_1=-8-(-13)=-8+13=5`

The nth term of an arithmetic sequence is

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

where, a is first term and d is common difference.

Substitute a=-13 and d=5 in the above formula.

`a_n=-13+(n-1)5`

`a_n=-13+5(n-1)`

Therefore, the correct option is B.