To represent a class of 30 students divided equally into 5 groups, you can use the division expression:
\[ \frac{30}{5} \]
This expression means that you are taking the total number of students (30) and dividing it by the number of groups (5). The result of this operation would give you the number of students in each group.
Alternatively, you could also express this as:
\[ 30 \div 5 \]
Both expressions represent the same operation and would yield the same result of 6 students per group.