The correct response is:
The sum or difference of two rational numbers is a rational number.
Here's why: The closure property states that when you perform a specific operation (like addition or subtraction) on numbers from a certain set (like rational numbers), the result will also belong to that set.
If you have a rational number and an irrational number, the sum of these two numbers cannot be rational. If it were rational, then you could rearrange the equation to show that the irrational number can be expressed in terms of rational numbers alone, which contradicts the definition of irrational numbers. Thus, it proves that the sum of a rational and an irrational number is irrational.