Which of the following best describes the solution to the equation below?

Note: Only consider the positive solution.
x^2 = 27

A.
It is an irrational number.

B.
It is a repeating decimal.

C.
It is a rational number.

D.
It is greater than zero but less than one.

1 answer

To solve the equation \( x^2 = 27 \), we take the square root of both sides:

\[ x = \sqrt{27} \]

We can simplify \( \sqrt{27} \) as follows:

\[ \sqrt{27} = \sqrt{9 \times 3} = \sqrt{9} \cdot \sqrt{3} = 3\sqrt{3} \]

Now, we need to determine the nature of the number \( 3\sqrt{3} \).

  1. Irrational Number: The number \( \sqrt{3} \) is an irrational number. Therefore, any multiple of it (such as \( 3\sqrt{3} \)) is also irrational.

  2. Repeating Decimal: Since \( 3\sqrt{3} \) is irrational, it cannot be expressed as a repeating decimal.

  3. Rational Number: \( 3\sqrt{3} \) is not a rational number since it cannot be written as a fraction of two integers.

  4. Greater than Zero but Less Than One: Clearly, \( 3\sqrt{3} \) is greater than zero because both 3 and \( \sqrt{3} \) are positive. However, \( \sqrt{3} \) is approximately \( 1.732 \), so \( 3\sqrt{3} \) is approximately \( 3 \times 1.732 = 5.196 \), which is greater than 1, not less than 1.

Based on the explanations, the best description of the positive solution \( x = 3\sqrt{3} \) is:

A. It is an irrational number.