Problem:
Real Estate Investments, Inc., owns and manages an office building. Secure Insurance Company agrees to lease the building for five years. Under the lease, Secure is obligated to pay all of the utility costs. Two years into the term, Secure asks Real Estate to modify the lease to provide that the utility costs be split equally between them. Real Estate agrees, but later decides it does not want to share the costs and refuses to pay. Is the landlord bound to its agreement to share the utility costs? Why or why not?