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I have the question in a screengrab. Thank you, whoever helps me.

I have the question in a screengrab. Thank you, whoever helps me.-example-1
User Fceller
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1 Answer

3 votes

To simplify


\sqrt[4]{(24x^6y)/(128x^4y^5)}

we need to use the fact that


\sqrt[4]{x^4}=|x|

Why the absolute value? It's because
(-x)^4=(-1)^4x^4=x^4.

We start by rewriting as


\sqrt[4]{(2^23x^6y)/(2^6x^4y^5)}


\sqrt[4]{(2^23x^4x^2y)/(2^42^2x^4y^4y)}

Since
x\\eq0, we have
\frac xx=1, and the above reduces to


\sqrt[4]{(3x^2y)/(2^4y^4y)}

Then we pull out any 4th powers under the radical, and simplify everything we can:


\frac1{\sqrt[4]{2^4y^4}}\sqrt[4]{(3x^2y)/(y)}


\frac1\sqrt[4]{3x^2}

where
y>0 allows us to write
\frac yy=1, and this also means that
|y|=y. So we end up with


\frac{\sqrt[4]{3x^2}}{2y}

making the last option the correct answer.

User Swithin
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