Final Answer:
The correct answer is (b) Teresa is correct.
Step-by-step explanation:
Rico and Teresa are discussing the nature of a given expression. To determine if it's a perfect square trinomial or the difference of two squares, let's consider an expression in the form a² - b² and another in the form a² + 2ab + b², where a and b are constants.
A perfect square trinomial is typically in the form a² + 2ab + b², and if 2ab is equal to the middle term of the given trinomial, then it is a perfect square trinomial. On the other hand, the difference of two squares is in the form a² - b².
For example, if the given expression is x² - 9, it can be factored as (x + 3)(x - 3), showing that it is the difference of two squares (x² - 3²).
In this context, Teresa is correct if the expression can be factored into the form a² - b², making it the difference of two squares. Rico would be correct if the expression can be factored into the form a² + 2ab + b², indicating a perfect square trinomial. The key lies in the factorization of the given expression, and based on that, Teresa is correct.