To express the number of pies donated \( n \) as a function of the number of weeks \( w \), you can use the equation:
\[ n = 13w \]
In this equation:
- \( n \) represents the number of pies donated.
- \( w \) represents the number of weeks.
- The coefficient \( 13 \) indicates that for each week, 13 pies are donated.
So, if you know the number of weeks, you can calculate the total number of pies donated by multiplying the number of weeks by 13.