Problem: Danielle and Heather are selling flower bulbs for a school fundraiser. Customers can buy packages of tulip bulbs and packages of crocus bulbs. Danielle sold 4 packages of tulip bulbs and 4 packages of crocus bulbs for a total of $76. Heather sold 1 package of tulip bulbs and 11 packages of crocus bulbs for a total of $169. What is the cost of 1 package of each kind of bulb? Set up and solve a system of equations to answer the question. Provide justifications and citations for your responses.