Question

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

Answer 1

Answer:

$a_n=-15+9(n-1)$

Step-by-step explanation:

The terms of the arithmetic sequence are...

-15, -6, 3, 12, ...

The first term is

a_1=-15

The common difference is

$d=-6--15=9$

The equation for the nth term is given by;

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

We substitute the values into the formula to get;

$a_n=-15+9(n-1)$

Answer 2

Answer:

D

Step-by-step explanation:

The n th term of an arithmetic sequence is

$a_{n}$ = a + (n - 1)d

where a is the first term and d the common difference

d = - 6 - (- 15) = - 6 + 15 = 9, and a = - 15

$a_{n}$ = - 15 + 9(n - 1)