Scroll down to Example C. In this activity, the examples and exercises require an extra step: substituting the values of the variables in the algebraic expressions. Then, they simply become numerical expressions, which can be evaluated by using order of operations agreement.
Work through Example C and Guided Practice problem 2, and then complete practice problems 8-10. Use the "Order of Operations Example" video embedded in the text for guidance. Once you have completed the practice problems, check your answers against the answer key.