I'm not completely sure, but I'm trying. You have 13% off, so you multiply y by .87. Then, you multiply the tax and total (.87y×.08y) to get the product of .0696y. After that step, you add the total and the product(.87y×.0696) and get the sum of .939y which will be your final answer.
For the expression, you can write Jason can use .939y to find the final cost of the cards.