Brenda is a purchasing agent for Commodities Exchange Corporation. Dennis, a Commodities corporate officer, gives Brenda written authority to buy for the firm as many computers and peripheral devices as necessary. The next day, Dennis calls Brenda and tells her to buy only fifty notebook computers and nothing else. Brenda shows the written authority to E-Products, Inc., and enters into a contract with E-Products to buy sixty note-book computers and a selection of printers, scanners, and extra storage media. E-Products ships the order to Commodities. Is Commodities liable to E-Products under the contract? Is Brenda liable? In each case, if so, why? If not, why not?