A school club is raising funds by having a "Shred It Day." To shred the documents, the club is charging $8 for the first three paper bags full of documents and $2 for each additional bag. a) Formulate a linear function that models the total cost C(x) of shredding x additional bags of documents. b) Graph the model. c) Use the model to determine the total cost of shredding 5 bags of documents. a) The total cost is given by C(x) = . (Do not factor.)