Question

Which Expression Can Be Used To Determine the nth term in the pattern below
20,25,30,35,40

Answer 1

see explanation

Explanation:

These are the terms of an arithmetic sequence with n th term

`a_(n)` = a + (n - 1)d

where a is the first term and d the common difference

d = 25 - 20 = 30 - 25 = 5 and a = 20, hence

`a_(n)` = 20 + 5(n - 1) = 20 + 5n - 5 = 5n + 15 ← n th term formula