You can put this solution on YOUR website!
By distributive property,
3(a+2) +a means the same as
3a+6 + 1a
Now combine like terms and you have
If you need help with this sort of problems, take a look at a page on my own website. To get to my website, do a "Bing" or "Google" search for my last name "Rapalje". Near the top of the search list, you will find "Rapalje Homepage." Then, near the top of my Homepage, you will find a link "Basic, Intermediate and College Algebra: One Step at a Time." Click on this link, and look for "Basic Algebra". Then choose "Chapter 1", and look for "Section 1.06 Variables and Distributive Property." The sections prior to this section may also be helpful to you. My own students used to tell me that my sections are a LOT easier to understand than the traditional books. Try it for yourself and see. It's all free.
Dr. Robert J. Rapalje, Retired
Seminole State College of Florida
Altamonte Springs Campus