First, set a variable.
Let x = the number of songs bought.
Each song costs 2 dollars. So, we have our first term: 2x.
And there is a fee of 5 dollars for using the website.
2x + 5
And she can't spend any more than 40 dollars. Which means she can spend 40 and under.
So, 2x + 5 ≤ 40 is the answer.