Dimitrius returned 5 library books last week, returned 3 books this week, and then checked out 8 more books. he now has 12 library books. how many books did he have before last week?

To solve this problem, we have to set up an equation. Let the variable x represent the number of books that Dimitrius had before last week. x - 5 - 3 + 8 = 12 To begin simplifying this equation, lets combine terms on the left side of the equation. x - 8 + 8 = 12 The -8 and +8 cancel each other out, leaving us with: x=12 Therefore, Dimitrius had 12 books before last week. Hope this helps! :)