The first term of an arithmetic sequence is 4 and the fifth term is 16. What is the nth term of the sequence?

A.

4n

B.

3n + 1

C.

5n - 1

D.

4n + 1

Aruthmetic

an=a1+d (n-1)

a1=4

5th is 16

a5=4+d (5-1) = 16

16=4+d (4)

minus 4

12=d (4)

divide 4

3=d

an=4+3 (n-1)

an=4+3n-3

an=4-3+3n

an=1+3n

B is ansres

If the 5th term is stated, all you need to do is plug in 5 for the n value, as it represents the 5th term. The only equation that holds true for the 5th terms being 16 is B. 3n+1

1st term = 3 (1) + 1 = 4

2nd term = 3 (2) + 1 = 7

3rd term = 3 (3) + 1 = 10

4th term = 3 (4) + 1 = 13

5th term = 3 (5) + 1 = 16

Correct answer is B. 3n+1