Final answer:
The inequality that represents this situation is 4s + 6l ≤ 100.
Step-by-step explanation:
To represent the situation where a catering company has small tables and large tables and wants to seat at most 100 guests, we can use the inequality 4s + 6l ≤ 100. Here, s represents the number of small tables and l represents the number of large tables. The inequality ensures that the total number of seats (4s for small tables and 6l for large tables) does not exceed 100.