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Evaluate \(\sqrt{20} \times (\sqrt{5})^3\)


Question

Evaluate \(\sqrt{20} \times (\sqrt{5})^3\)

Options

A) 10

B) 20

C) 25

D) 50

The correct answer is D.

Explanation:

\(\sqrt{20} = \sqrt{4} \times \sqrt{5}\)
And \(\sqrt{4} = 2\)
So \(\sqrt{20} = 2 \times \sqrt{5}\)
\((\sqrt{5})^3 = 5 × \sqrt{5}\)
Multiplying both sides:
\((2 \times \sqrt{5}) \times (5 \times \sqrt{5})\)
\(= 10 \times 5 = 50\)

Explanation provided by Olalere Eniolaoluwa


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Dicussion (1)

  • \(\sqrt{20} = \sqrt{4} \times \sqrt{5}\)
    And \(\sqrt{4} = 2\)
    So \(\sqrt{20} = 2 \times \sqrt{5}\)
    \((\sqrt{5})^3 = 5 × \sqrt{5}\)
    Multiplying both sides:
    \((2 \times \sqrt{5}) \times (5 \times \sqrt{5})\)
    \(= 10 \times 5 = 50\)