The images you provided both describe the concept of an empty set in mathematics.

For the first image, the correct answer to complete the sentence "A set that contains no elements is called the ___ set and is represented by ___" is:

1. empty/null set and is represented by {∅} or {}.

For the second image, the correct answers for the blanks are:

1. A set that contains no elements is called the empty/null set.
2. It is represented by {∅} or {}.

Would you like to dive deeper into any specific mathematical concepts related to sets or clarify anything further? Let me know!

Related questions:

1. What are the main types of sets in mathematics?
2. How do you represent infinite sets?
3. What is the difference between a finite set and an infinite set?
4. How do set operations work, like union and intersection?
5. What is a subset, and how is it represented?

Tip: The empty set is the foundation for many concepts in set theory and mathematics, and it has a unique property: it is a subset of every set.