To formulate the equation based on the situation described, we can start by defining the two variables:
- Let \( s \) be the number of student tickets sold.
- Let \( t \) be the number of other tickets sold.
We know the following from the problem:
- The price of a student ticket is $3.
- The price of an "other" ticket (not a student ticket) is $5.
- The total sales from the tickets amounted to $779.
We can express the total revenue from the tickets sold as the sum of the revenue from student tickets and the revenue from other tickets:
\[ 3s + 5t = 779 \]
This equation relates the number of student tickets sold \( s \) and the number of other tickets sold \( t \).
To write it in standard form, we typically want the equation to be in the form \( Ax + By = C \) where \( A \), \( B \), and \( C \) are integers. However, the equation \( 3s + 5t = 779 \) is already in standard form.
Thus, the final answer is:
\[ 3s + 5t = 779 \]