Commutative and Associative Properties
Read this section up to example 7.6. Then, do example 7.6 and Try It exercises 7.11 and 7.12.
Click https://cnx.org/contents/yqV9q0HH@19.9:nmU2s-CD@20/7-2-Commutative-and-Associative-Properties link to open resource.