According to the statement, Kharon needs to write 3 book reports with b pages. This means that he has 3 books and each of them has b amount of pages which you can express as b+b+b that is equal to 3b. Also, he has 3 science reports with s pages which is 3s. In order to find the total number of pages, you have to add up 3b plus 3s. According to this, the algebraic expression for the total number of pages Kharon will need to write is: 3b+3s.
