For school, Georgia bought 6 notebooks and 2 folders. Let n represent the cost of each notebook and f represent the cost of each folder. Write an expression to determine the total cost for the school supplies. Then, calculate the cost if each notebook costs fifty cents and each folder costs two dollars.
two n plus six f; seven dollars
two n plus six f; thirteen dollars
six n plus two f; thirteen dollars
six n plus two f; seven dollars