To determine the type of number that results from the expression \( 512 \cdot \sqrt{16} \), let's analyze both components of the expression:
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Evaluating \( \sqrt{16} \): \[ \sqrt{16} = 4 \] Since \( 4 \) is a rational number, we now have: \[ 512 \cdot 4 \]
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Evaluating \( 512 \cdot 4 \): \[ 512 \cdot 4 = 2048 \] Since \( 2048 \) is also a rational number, the overall result is rational.
Explanation of the Responses:
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"Rational, because both numbers are rational.": This response is correct because both \( 512 \) and \( \sqrt{16} \) (which equals \( 4 \)) are rational numbers, and the product of two rational numbers is always rational.
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"Irrational, because both factors are irrational.": This response is incorrect because \( \sqrt{16} = 4 \) is not an irrational number; it is a rational number.
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"Radical, because one factor is a radical.": The term "radical" is sometimes used informally, but it's not a classification of the number itself. In this case, while one factor is indeed a radical (\( \sqrt{16} \)), the result of the entire operation is still a rational number, so this sounds inaccurate.
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"Irrational, because one factor is irrational.": This response is incorrect and could be misleading because the factor \( \sqrt{16} \) is not irrational. Thus, the presence of an irrational factor does not apply here.
Summary:
The correct classification is rational because both initial numbers are rational, and their product results in a rational number.