# How do you find the nth term rule for #34,25,16,7,-2,...#?

##### 1 Answer

#### Answer:

If you consider

If you consider

#### Explanation:

First of all, we need to see that the rule of the sequence is "subtract nine", and I suppose that this is the easy part.

Now, we need to see the sequence with the point of view of the first term: we start with *twice* from

This should lead you to the general rule: start with a number, subtract **once** to obtain the **second** number, subtract **twice** to obtain the **third** number...and so on.

Using a proper notation, if we define

which would be your closed formula for

NB: if you choose to start with