Greg paid $33 for 2 shirts and $48 for 3 shirts, including a fixed shipping fee. Assuming the same function applies to any number of shirts bought, answer the following questions.

How much, in dollars, would 1 shirt cost before the shipping fee? Enter your answer in the first box.

If the equation was written as y = mx +b and if the shipping fee was increased, which constant would change? Enter
your answer in the second box.

If the equation was written as y = mx + b and if the cost per shirt was increased, which constant would change?
Enter your answer in the third box.