Question

timed problem
score: 4/10 current time: 108.9
select the most simplified equivalent.
$4\sqrt{5}\cdot 5$
answer
$20\sqrt{5}$
$4\sqrt{5}\cdot 5$
$4\sqrt{25}$
$20\sqrt{25}$
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Explanation:

Step1: Simplify the coefficient multiplication

Multiply the constants outside the radical:
$4 \times 5 = 20$

Step2: Combine with the radical term

Keep the simplified radical and combine with the new coefficient:
$20\sqrt{5}$

Step3: Verify other options

• $4\sqrt{5} \cdot 5$: Uncombined constants, not simplified
• $4\sqrt{25}$: $\sqrt{25}=5$, so this equals $20$, not equivalent
• $20\sqrt{25}$: $\sqrt{25}=5$, so this equals $100$, not equivalent

Answer:

$20\sqrt{5}$