Riley and her friends buy snacks at the movies. They buy 3 pretzels and 4 drinks for $17.50. The cost of a pretzel is the same as the cost of a drink. The situation can be represented by the graph and the system of equations shown, where p is the cost of a pretzel and dis the cost of a drink. I a. What is the cost of each pretzel? What is the cost of each drink? Show your work.