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43 votes
43 votes
Simplfy the Radical 18) 9*sqrt(125)

User Hitarth
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1 Answer

16 votes
16 votes

Given the expression:


9\cdot\sqrt[]{125}

notice that for 125 we have the following:


125=5^3

therefore, we can simplify the expression by using 5^3 to get the following:


9\cdot\sqrt[]{125}=9\cdot\sqrt[]{5^3}=9\cdot\sqrt[]{5^2\cdot5}

now, remember that when we have a product inside a square root, we can split it on both factors. In general, for any exponent, we have the following rule:


\begin{gathered} (a\cdot b)^n=a^nb^n \\ \text{ in this case:} \\ \sqrt[]{a\cdot b}=\sqrt[]{a}\cdot\sqrt[]{b} \end{gathered}

then, for our expression at hand, we have:


9\cdot\sqrt[]{5^2\cdot5}=9\cdot\sqrt[]{5^2}\cdot\sqrt[]{5}=9\cdot5\cdot\sqrt[]{5}=45\sqrt[]{5}

therefore, the simplifed expression is 45*sqrt(5)

User Mickaelw
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3.2k points