Question

An arithmetic sequence is defined by the equations a1 = 10 and an = an-1 + 6. What is the third term of

An = an-1 + 6?

Answer 1

The correct answer is 22

Explanation:

We have that
`a_(1)` is 10

and the general formule is an=
`a_(n-1)` +6

taking n=3 and replacing it on the general equation, we have:

`a_(3)` =
`a_(2)` +6 (1)

We don't know the term
`a_(2)`, we can look for it occupying the general equation again:

`a_(2)` =
`a_(1)` +6 (2)

Replacing
`a_(1)` on (2):

`a_(2)` = 10 +6 = 16 (3)

And finally replacing (3) on (1) we get te correct answer;

`a_(3)` = 16+6 = 22

Answer 2

22

Explanation:

You are given term is equal to previous term plus 6.

a1=10

a2=10+6=16

a3=16+6=22