Final answer:
The inequality that represents the possible values for the number of hours Madelyn can work in a given week is w + d ≤ 8.
Step-by-step explanation:
To represent the possible values for the number of hours washing cars (w) and the number of hours walking dogs (d) that Madelyn can work in a given week, we can set up the following inequality:
w + d ≤ 8
This inequality states that the sum of the hours spent washing cars and walking dogs should be less than or equal to 8 hours, which is the maximum number of hours Madelyn can work in a week.