The Odyssey Owls are having school t-shirts made. One option is to pay Ashley's Tees a $20 setup fee and pay $6 for each shirt. Another option is to pay City Printing a $40 setup fee and $4 per shirt. The person in charge of ordering the shirts notices that, with a certain number of shirts, the two options would have the same exact cost. What is the number of shirts that could be made and the price be the same from both companies? What equation could you write for Ashley's Tees if x = number of shirts and y = total cost?