If you have $272, and you spend $17 each day, how long would it be until you had no money left?

If you have $272, and you spend $17 each day, how long would it be until you had no money left?

Let d be the number of days. We have a balance expression of:
272 - 17d

We want to know when the balance is 0, so we set 272 - 17d equal to 0.
272 - 17d = 0

To solve for d, we type this equation into our search engine and we get:
d = 16