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Write problem as a single radical using the smallest possible root. 20

Write problem as a single radical using the smallest possible root. 20-example-1
User Theo Deep
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1 Answer

25 votes
25 votes

Answer::


\sqrt[30]{r^(29)}

Explanation:

Given the expression:


\sqrt[5]{r^4}\sqrt[6]{r}

First, rewrite the expression using the fractional index law:


\begin{gathered} \sqrt[n]{x}=x^{(1)/(n)} \\ \implies\sqrt[5]{r^4}=r^{(4)/(5)};\text{ and} \\ \sqrt[6]{r}=r^{(1)/(6)} \end{gathered}

Therefore:


\sqrt[5]{r^4}*\sqrt[6]{r}=r^{(4)/(5)}* r^{(1)/(6)}

Use the multiplication law of exponents:


\begin{gathered} a^x* a^y=a^(x+y) \\ \implies r^{(4)/(5)}* r^{(1)/(6)}=r^{(4)/(5)+(1)/(6)} \\ (4)/(5)+(1)/(6)=(24+5)/(30)=(29)/(30) \\ \operatorname{\implies}r^{(4)/(5)}* r^{(1)/(6)}=r^{(4)/(5)+(1)/(6)}=r^{(29)/(30)} \end{gathered}

The resulting expression can be rewrittem further:


\begin{gathered} r^{(29)/(30)}=(r^(29))^{(1)/(30)} \\ =\sqrt[30]{r^(29)} \end{gathered}

The single radical is:


\sqrt[30]{r^(29)}

User Moishe Lettvin
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