Question

A sequence is defined recursively using the formula f(n + 1) = f(n) – 5 . Which sequence could be generated using this formula?

1, –5, 25, –125, ...
2, 10, 50, 250, ...
3, –2, –7, –12, ...
4, 9, 14, 19, ...

Answer 1

3, –2, –7, –12, ...

Explanation:

f(n+1) = f(n) − 5

This means each term is 5 less than the term before it.

The only option that works is the third one.