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Mathematics 7 Online
OpenStudy (-welp-):

How does this equal that(problem inside)?

OpenStudy (-welp-):

\[\frac{ \sqrt[3]{5} }{ \sqrt[3]{st^2} } = \frac{ \sqrt[3]{5s^2t} }{ st }\] My Steps: \[\frac{ \sqrt[3]{5} }{ \sqrt[3]{st^2} } * \frac{ \sqrt[3]{st^2} }{ \sqrt[3]{st^2} } * \frac{ \sqrt[3]{st^2} }{ \sqrt[3]{st^2} } = \frac{ \sqrt[3]{5s^2t^6} }{ \sqrt[3]{s^3t^6} }\] I don't know where I went wrong

OpenStudy (agent0smith):

\[\Large \frac{ \sqrt[3]{5} }{ \sqrt[3]{st^2} } * \frac{ \sqrt[3]{st^2} }{ \sqrt[3]{st^2} } * \frac{ \sqrt[3]{st^2} }{ \sqrt[3]{st^2} } = \frac{ \sqrt[3]{5s^2t^6} }{ \sqrt[3]{s^3t^6} }\]your font was too small on my screen.

OpenStudy (agent0smith):

You did too much work, for one. Make it easier like so: \[\Large \frac{ \sqrt[3]{5} }{ \sqrt[3]{st^2} }*\frac{ \sqrt[3]{s^2 t} }{ \sqrt[3]{s^2 t} }\] all you need to do is get the exponents under the bottom cube root to be 3's

OpenStudy (-welp-):

Where did you get this from? \[\frac{ \sqrt[3]{s^2t} }{ \sqrt[3]{s^2t} }\]

jimthompson5910 (jim_thompson5910):

@agent0smith in order to rationalize the denominator, you need to multiply by two copies of the denominator

OpenStudy (agent0smith):

No you don't...

OpenStudy (cieloveswork):

just get photomath it works for everything but graphs and word problems https://www.photomath.net/en/

OpenStudy (agent0smith):

You want the exponents under that cube root to all become 3's, so figure out how many to put on each Eg. if you had \[\Large \frac{ 5 }{ \sqrt[100]{x}}\] then you do this \[\Large \frac{ 5 }{ \sqrt[100]{x}}*\frac{ \sqrt[100]{x^{99}} }{ \sqrt[100]{ x^{99} }}\]

jimthompson5910 (jim_thompson5910):

Example: \[\Large \frac{1}{\sqrt[3]{x}} = \frac{1}{\sqrt[3]{x}}*{\color{red}{\frac{\sqrt[3]{x}}{\sqrt[3]{x}}}}*{\color{red}{\frac{\sqrt[3]{x}}{\sqrt[3]{x}}}}\] \[\Large \frac{1}{\sqrt[3]{x}} = \frac{\sqrt[3]{x}*\sqrt[3]{x}}{\sqrt[3]{x}*\sqrt[3]{x}*\sqrt[3]{x}}\] \[\Large \frac{1}{\sqrt[3]{x}} = \frac{\sqrt[3]{x*x}}{\sqrt[3]{x*x*x}}\] \[\Large \frac{1}{\sqrt[3]{x}} = \frac{\sqrt[3]{x^2}}{\sqrt[3]{x^3}}\] \[\Large \frac{1}{\sqrt[3]{x}} = \frac{\sqrt[3]{x^2}}{x}\]

OpenStudy (agent0smith):

@jim_thompson5910 do you want to try that with my previous example...? No, you multiply by enough exponents that add up to the root exactly.

jimthompson5910 (jim_thompson5910):

true it does work, so that's a valid alternative

OpenStudy (cieloveswork):

hey @agent0smith can you hlp me with a WORD PROBLEM

OpenStudy (agent0smith):

I learned it this way from an algebra 2 book, teaching it a couple of years ago in general:\[\Large \frac{ 1 }{ \sqrt[a]{x^b} }*\frac{ \sqrt[a]{x^{a-b}} }{ \sqrt[a]{x^{a-b}} }\]

OpenStudy (agent0smith):

@-Welp- the way you did it is fine too, but that last exponent should be a 4, i fixed it \[\Large \frac{ \sqrt[3]{5} }{ \sqrt[3]{st^2} } * \frac{ \sqrt[3]{st^2} }{ \sqrt[3]{st^2} } * \frac{ \sqrt[3]{st^2} }{ \sqrt[3]{st^2} } = \frac{ \sqrt[3]{5s^2t^4} }{ \sqrt[3]{s^3t^6} }\]

OpenStudy (agent0smith):

then just simplify a little\[\Large \frac{ \sqrt[3]{5s^2t^4} }{ \sqrt[3]{s^3t^6} } = \frac{ t\sqrt[3]{5s^2t} }{ st^2 } \]

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