Matt has started a car washing business to save money for college. each week he washes three more cars than the week he did before.

This problem can be expressed as a liner model, because it specifies that each week he washes three more cars than the week before, this means that the new week is always three more than the previous week, this implies a sum operation to indicate it.

So, the expression would be:

Where represents the new week, and represents the previous week.

a. she will receive a refund of $278.

step-by-step explanation: