The expression you provided is:

$a^3 b^2 - a$

This is a polynomial involving two variables, $a$ and $b$.

If you're asking to simplify or factor it, we can factor out the common term $a$ from the two terms:

$a(a^2 b^2 - 1)$

This is the factored form of the expression.

Would you like to explore more details about how to handle this expression, or is there a specific operation you'd like to perform on it?

Here are some related questions you might find interesting:

1. How do we factor expressions with multiple variables?
2. What is the difference between a polynomial and a binomial?
3. How would you expand the factored form of $a(a^2 b^2 - 1)$?
4. What is the role of exponents in algebraic expressions like $a^3 b^2$?
5. How do you solve equations involving polynomials?

Tip: Remember that factoring can simplify equations and make it easier to find solutions, especially when solving for unknowns!