Work Step by Step
We start by distributing -1 to the terms in the first set of parentheses. We have $-(3a-2b)-3(-a-b)=-3a+2b-3(-a-b)=-3a+2b+3a+3b=5b$.
You can help us out by revising, improving and updating this answer.Update this answer
After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.