Let \( x \) represent the number of books in the school library. According to the problem, the town library has 3 times as many books as the school library, and the town library has 2,676 books.
The relationship can be expressed as:
\[ 3x = 2676 \]
This equation can be used to find the number of books in the school library.
So, the multiplication equation that can be used is \( 3x = 2676 \).