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OpenStudy (18jonea):

Rationalize the denominator of

OpenStudy (18jonea):

@calculusxy

OpenStudy (18jonea):

@agent0smith

OpenStudy (18jonea):

@TheSmartOne

OpenStudy (18jonea):

@Anaise

TheSmartOne (thesmartone):

To rationalize the denominator, multiply the top and bottom by whatever is in the square root of denominator because \(\sqrt{a} \times \sqrt{a} = a\) so for example \(\Large\frac{1}{\sqrt{2}} = \frac{1}{\sqrt{2}} \times \frac{\sqrt{2}}{\sqrt{2}} =\boxed{\bf{\frac{\sqrt{2}}{2} }}\)

TheSmartOne (thesmartone):

rationalizing the denominator basically means removing the square root from the denominator

OpenStudy (18jonea):

so the 6?

TheSmartOne (thesmartone):

what is under the square root in the question, not the answer choices

OpenStudy (18jonea):

6

OpenStudy (18jonea):

its \[\sqrt{6}\]

OpenStudy (18jonea):

@TheSmartOne

TheSmartOne (thesmartone):

http://prntscr.com/bknf6b

TheSmartOne (thesmartone):

I said the question, not the answer choices.

OpenStudy (18jonea):

no i know the denomentor has square root 6

OpenStudy (18jonea):

@TheSmartOne

TheSmartOne (thesmartone):

what is in the red box? http://prntscr.com/bknf6b

OpenStudy (18jonea):

oh my gosh i just realized that i was looking at the wrong problem... that is why i was saying 6.... sorry

TheSmartOne (thesmartone):

I was wondering what was wrong, haha

OpenStudy (18jonea):

5zr is in the red box

OpenStudy (18jonea):

i am so sorry

TheSmartOne (thesmartone):

so, we have to multiply top and bottom by it \(\Large\bf \frac{\sqrt{20z^2r}}{\sqrt{5zr}} \times \frac{\sqrt{5zr}}{\sqrt{5zr}} =\)

OpenStudy (18jonea):

so would i multiply 100z^3r^2 for the numerator or no?

TheSmartOne (thesmartone):

that's correct, and it's under a sqrt

OpenStudy (18jonea):

right

TheSmartOne (thesmartone):

and what would the denominator be?

OpenStudy (18jonea):

ok so what do i have to do?

OpenStudy (18jonea):

25z^2 r^2

OpenStudy (18jonea):

under a sqrt

TheSmartOne (thesmartone):

remember \(\sqrt{a} \times \sqrt{a} = a\) if we use that, then the denominator simply loses the sqrt sign and becomes 5zr do you understand?

OpenStudy (18jonea):

oh got it

TheSmartOne (thesmartone):

now let's simplify \(\sqrt{100z^3r^2}\)

OpenStudy (18jonea):

10 is sqrt of 100 r is squrt of r

OpenStudy (18jonea):

@TheSmartOne

TheSmartOne (thesmartone):

and here is another hint: \(\sqrt{z^3} = \sqrt{z^2 \times z} = \sqrt{z^2}\sqrt{z} = \)

OpenStudy (18jonea):

so \[2\sqrt{z}\]

OpenStudy (18jonea):

@TheSmartOne

TheSmartOne (thesmartone):

not sure where that 2 came from remember this rule: \(\sqrt{a^2} = a\)

OpenStudy (18jonea):

\[\sqrt{z^2}\]

OpenStudy (18jonea):

@TheSmartOne

TheSmartOne (thesmartone):

mhmmm, no \(\sqrt{z^3} = \sqrt{z^2 \times z} = \sqrt{z^2}\sqrt{z} = \) so simplify \(\sqrt{z^2}\)

OpenStudy (18jonea):

or just \[\sqrt{z}\]

OpenStudy (18jonea):

z

OpenStudy (18jonea):

@TheSmartOne

TheSmartOne (thesmartone):

yes, so it is \(z\sqrt{z}\)

TheSmartOne (thesmartone):

now we have \(\Large\frac{10zr\sqrt{z}}{5zr}\)

OpenStudy (18jonea):

ok so 10/5 is 2 zr ar cancelled out so that leaves \[2\sqrt{z}\]

OpenStudy (18jonea):

@TheSmartOne

TheSmartOne (thesmartone):

yes :)

OpenStudy (18jonea):

I have a couple more like this could you help me with them?

OpenStudy (18jonea):

?

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