<span>you have"a" as common so, you can write it as: a(3b+1) +3b^2 + b. from the remaining two terms, you have b common, so write it as a(3b+1) +b(3b+1).
This gives you (a+b)(3b+1) </span> I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!