Answer:
The number of students on each bus is;

And the expression is;

Step-by-step explanation:
Let X represent the number of students on each bus.
Assuming the buses were filled with the same number of students.
Given that all 6 buses were filled and 4 students had to travel in cars.
We can write the expression as;

Equating to the total number of students;

Solving for X;

Therefore, the number of students on each bus is;
