Question

Find the 13th term of the arithmetic sequence whose common difference is d=7 and whose first term is (see photo attached)

Answer 1

Answer:

Step-by-step explanation:

The formula for an arithmetic sequence is

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

where n is the position of the number you are looking for, a₁ is the first number in the sequence, and d is the common difference.  We are given the following information:

n = 13,

a₁ = 5, and

d = 7

Filling in our formula then looks like this:

$a_{13}=5+7(13-1)$ and

$a_{13}=5+7(12)$ and

$a_{13}=5+84$ so

the 13th term in our sequence is 89