JJ owns a bakery and makes daily batches of pies and cookies. One pie requires 2 cups of flour to make the crust, and one batch of cookies requires 3.5 cups of flour. JJ has 28 cups of flour to use. Let x equal the number of pies and let y equal the number of batches of cookies.
Give a combination of pies and cookies that JJ can make. Explain how you know the combination works.