Question

The third term in a sequence is 11.

The term-to-term rule is "take away four".
Write an expression, in terms of n, for the nth term of the sequence.

Answer 1

4n-1

Explanation:

The difference in the numbers is 4 so the coefficient must be 4 for the nth term meaning

4n

11 is the third term however we need to find the first so..

11=3rd term

-4

7=2nd term

-4

3=1st term

now we need to minus 4 from 3 which is -1 (3-4)

meaning the answer put together will be 4n-1