How does the Closure Property prove that the sum of a rational and irrational number is irrational?(1 point)

Responses

The sum or difference of a rational and irrational number is a rational number.
The sum or difference of a rational and irrational number is a rational number.

The sum or difference of two rational numbers is a rational number.
The sum or difference of two rational numbers is a rational number.

The sum of an irrational and rational number can’t be predicted.
The sum of an irrational and rational number can’t be predicted.

Irrational numbers can be added or subtracted.

1 answer

To show that the sum of a rational and irrational number is irrational, we can use the closure property of rational numbers. The key point is:

  • The sum or difference of a rational number and an irrational number is not a rational number.

Thus, the correct response based on the concept would be:

The sum or difference of a rational and irrational number is a rational number. (This statement is incorrect, as it should be the opposite: it results in an irrational number.)

To clarify:

  1. A rational number can be expressed as a fraction of two integers (e.g., \( \frac{a}{b} \)).
  2. An irrational number cannot be expressed as such a fraction (e.g., \( \sqrt{2} \)).
  3. If you add a rational number \( r \) to an irrational number \( i \), you would have \( r + i \), which cannot be expressed as a fraction of integers, thus it remains irrational.

Since the statements you've provided contain redundancies and inaccuracies, the conclusion that the sum of a rational and an irrational number is irrational primarily stands on the understanding that if you add a rational to an irrational number, it will not yield a rational result, thereby proving that the sum is irrational.