Question

Which of the following equations represents the nth term of the arithmetic sequence?18, 23, 28, 33, 38, … an = 18 + 5n an = 18 − 5n an = 18 + 5(n − 1) an = 18 − 5(n − 1)

Answer 1

We have to find the arithmetic sequence formula.

The first term is 18 and the common difference would be 5.

Replacing in the formula, we have:

an= a1 + (n-1)d

an= 18 + (n-1)5

an= 18 + 5(n-1) (Reorganizing)

The answer is the third option an= 18 + 5(n-1).