Your class is planning a breakfast bake sale and you have been tasked to bake the donuts and bagels. The system below represents the total amount of flour, in pounds, needed to replicate a batch-of-six bagel recipe and a batch-of-twelve donut recipe. You will be replicating the donut recipe d number of times and the bagel recipe b number of times. 3d + 5b = 21 d + b = 5