A donut shop offers a discount on purchases of donuts and coffee that total more than 10 items. Cynthia orders 8 donuts and 4 cups of coffee for a total of $16. While Cynthia is waiting for her order, another customer orders 4 donuts and 8 cups of coffee for a total of $17. Let d represent the discounted cost of a donut and c represent the discounted cost of a cup of coffee. Which equations will help Cynthia solve for the values of d and c?
​