Question

What is the 30th term of the arithmetic series 2, 5, 8, … ?

Answer 1

`89`

Explanation:

One way to tackle this would be to count up all the way to the 30th term.

The more elegant way would be to create a linear equation, where `f(x)` is the number in the sequence and `x` is the term number.

We can see that the arithmetic sequence rises by `3` each term, so `3` is our slope. We also know that the first term is `2` (when `x=1`), so we can figure out that our equation must be `f(x)=3x-1`.

With this, we can plug in `30` for `x` and get `color(red)(89)`.