Notice the sign gets reversed when you divide or multiply by a negative number.
The only option less than -2 is -3, A.
Here's a tip: on multiple choice questions, sometimes it's faster to try each answer instead of solving the equation. This can save time on tests like the SAT or ACT.
The 10$ is added on because it's a one time exchange and the 8 is multiplied by the x because for every hour you add 8$ to the price and y is the total price at the end depending on x.