Question

What are the first three terms of the sequence defined by the following equation? a_n= 7 + (n - 1) 5

7, 2, -3

7, 12, 17

7, 35, 175

12, 17, 22

Answer 1

7, 12, 17 which is the second choice

Explanation:

The given sequence is expressed by the equation

`a_n = 7 + (n - 1)5\\\\(n - 1)5 = 5n - 5\\\\a_n = 7 + (n - 1)5= 7 + 5n - 5\\\\= 2 + 5n\\\\a_n = 5 + 2n\\\\a_1 = 2 + 5(1) = 2 + 5 = 7\\\\a_2 = 2 + 5(2) = 2 + 10 = 12\\\\a_3 = 2 + 5(3) = 2 + 15 = 17\\\\`

So the first three terms are
7, 12, 17 which is the second choice