Let x be the maximum amount of tickets that Ms. H can buy.
Since each ticket costs $15.5, if she buys x tickets, she would spend 15.50x dollars.
Since she also have to pay for the parking, which costs $7, then the total amount of money that she spends buying x tickets and paying for parking, is:

Since she has $100 to spend, this expression should be equal to $100 if she buys all the tickets that she can.
Therefore, the equation that can be used to determine the number x of people that she can bring to the zoo, is:
