Let's analyze each option to determine which one is a monomial:

1. mc001-1.jpg – I don't have the ability to view the image directly. Please upload the image, and I can analyze it for you.

2. mc001-2.jpg – Same as above, please upload this image for further analysis.

3. x + 1 – This is a binomial because it contains two terms, "x" and "1". A monomial contains only one term.

4. 7 – This is a monomial because it is a single constant number (which can also be viewed as a term).

Conclusion:

The monomial expression here is 7.

Would you like to upload the images so I can analyze them as well? Or do you have any other questions about this?

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Here are 5 related questions for you:

1. What is the definition of a monomial?
2. How do you classify expressions as binomials or polynomials?
3. Can a monomial contain variables and constants together?
4. What is the degree of a monomial?
5. What are some examples of non-monomial expressions?

Tip:

A monomial must be a single term. If there are two or more terms connected by addition or subtraction, it is not a monomial.