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Mathematics 21 Online
OpenStudy (anonymous):

Help please?

OpenStudy (anonymous):

OpenStudy (marissalovescats):

I used to remember how to do these.. but it's been a long time so I'm going to link a person who's likely to remember and is able to teach it very well @jim_thompson5910

jimthompson5910 (jim_thompson5910):

First we'll use this rule \[\Large \frac{\sqrt[n]{A}}{\sqrt[n]{B}} = \sqrt[n]{\frac{A}{B}}\] ------------------------------------------------------- Using that rule, we go from this \[\Large \frac{\sqrt[4]{32x^{11}y^{15}}}{\sqrt[4]{2x^3y^{-2}}}\] to this \[\Large \sqrt[4]{\frac{32x^{11}y^{15}}{2x^3y^{-2}}}\]

OpenStudy (anonymous):

ahh i knew it was something like that. so can i divide 32/2?

jimthompson5910 (jim_thompson5910):

which is what?

OpenStudy (anonymous):

16. and for the variables i just subtract? so x^11-3 and y^15-(-2)?

OpenStudy (anonymous):

so would it be 2x^8y^17? @jim_thompson5910

jimthompson5910 (jim_thompson5910):

Sorry this site is being buggy

jimthompson5910 (jim_thompson5910):

but yeah, you subtract the exponents for the corresponding variables

jimthompson5910 (jim_thompson5910):

32/2 = 16, so you should have this so far \[\Large \sqrt[4]{16x^{8}y^{17}}\]

OpenStudy (anonymous):

it said that my answer was wrong though:c i know for the fact that 2^4=16

jimthompson5910 (jim_thompson5910):

What's your next move?

OpenStudy (anonymous):

if i square root 16 it would be 4? so do i just write "4(x^8y^17)^(1/4)?

OpenStudy (anonymous):

or 4x^2(x^2y^17)^(1/4)? @jim_thompson5910

jimthompson5910 (jim_thompson5910):

we have this \[\Large \sqrt[4]{16x^{8}y^{17}}\]

jimthompson5910 (jim_thompson5910):

we then rewrite that as \[\Large \left(16x^{8}y^{17}\right)^{1/4}\]

jimthompson5910 (jim_thompson5910):

and then apply that outer exponent of 1/4 to everything inside \[\Large \left(16x^{8}y^{17}\right)^{1/4} = 16^{1/4}*\left(x^{8}\right)^{1/4}*\left(y^{17}\right)^{1/4}\]

jimthompson5910 (jim_thompson5910):

what's next?

OpenStudy (anonymous):

im completely lost... so 2^4=16? and to simplify x^8 it would be (x^2)^4? @jim_thompson5910

jimthompson5910 (jim_thompson5910):

Do you see how I got up to \[\Large 16^{1/4}*\left(x^{8}\right)^{1/4}*\left(y^{17}\right)^{1/4}\] ??

OpenStudy (anonymous):

i see it because the radical expression had 4.... right? so 16/4=2 and checking 2^4 it equals 16. i just don't get how to simplify the variables

jimthompson5910 (jim_thompson5910):

yep so because \[\Large 2^4 = 16\] this means \[\Large \sqrt[4]{16} = \sqrt[4]{2^4}\] \[\Large \sqrt[4]{16} = \left(2^4\right)^{1/4}\] \[\Large \sqrt[4]{16} = 2^{4*(1/4)}\] \[\Large \sqrt[4]{16} = 2^{1}\] \[\Large \sqrt[4]{16} = 2\]

jimthompson5910 (jim_thompson5910):

For the x term, you do the same thing \[\Large \left(x^{8}\right)^{1/4} = x^{8*(1/4)}\] \[\Large \left(x^{8}\right)^{1/4} = x^{2}\]

jimthompson5910 (jim_thompson5910):

What do you when you simplify the y term?

OpenStudy (anonymous):

for y^17... would you put it in radical form?

jimthompson5910 (jim_thompson5910):

how would you simplify \[\Large \left(y^{17}\right)^{1/4}\]

OpenStudy (anonymous):

y^17/4?

jimthompson5910 (jim_thompson5910):

what is 17/4 equal to?

OpenStudy (anonymous):

4.25?

jimthompson5910 (jim_thompson5910):

fill in these blanks 17/4 = _____ remainder _____

OpenStudy (anonymous):

4 remainder of 25?

jimthompson5910 (jim_thompson5910):

the first part is right, but having a remainder of 25 is not

jimthompson5910 (jim_thompson5910):

4 goes into 17 four whole times since 4*4 = 16

jimthompson5910 (jim_thompson5910):

the remainder is the amount left over 17 - 16 = 1

jimthompson5910 (jim_thompson5910):

17/4 = 4 remainder 1

OpenStudy (anonymous):

ohhh

jimthompson5910 (jim_thompson5910):

why do we care about this? well because we can use that quotient/remainder to convert 17/4 to a mixed number \[\Large \frac{17}{4} = 4\frac{1}{4}\]

jimthompson5910 (jim_thompson5910):

so... \[\Large \left(y^{17}\right)^{1/4} = y^{17/4}\] \[\Large \left(y^{17}\right)^{1/4} = y^{4 \frac{1}{4}}\] \[\Large \left(y^{17}\right)^{1/4} = y^{4 + \frac{1}{4}}\] \[\Large \left(y^{17}\right)^{1/4} = y^{4}*y^{\frac{1}{4}}\] \[\Large \left(y^{17}\right)^{1/4} = y^{4}*\sqrt[4]{y^1}\] \[\Large \left(y^{17}\right)^{1/4} = y^{4}*\sqrt[4]{y}\]

jimthompson5910 (jim_thompson5910):

In other words, I'm saying \[\Large \sqrt[4]{y^{17}} = y^{4}*\sqrt[4]{y}\]

OpenStudy (anonymous):

so would it be...\[2x ^{2}y ^{4}\sqrt[4]{y}\]?

jimthompson5910 (jim_thompson5910):

that's one form of the final answer however, they want all radicals to be in exponential form so \[\Large 2x^2y^4\sqrt[4]{y} = 2x^2y^4y^{\frac{1}{4}}\]

OpenStudy (anonymous):

ohh okay another question.. how would the text format be when i enter it in? would it just be 2x^2y^4y^1/4?

jimthompson5910 (jim_thompson5910):

enclose the exponent in parenthesis to make sure the computer knows that 1/4, and not just 1, is the exponent.

OpenStudy (anonymous):

so for sure that the system wants it in exponential form?

jimthompson5910 (jim_thompson5910):

hmm now that I think about it, it's probably just more efficient and time-saving to just write 2x^2y^(17/4)

jimthompson5910 (jim_thompson5910):

it says so on the problem posted

OpenStudy (anonymous):

it said that it was wrong:c

jimthompson5910 (jim_thompson5910):

for \[\Large \sqrt[n]{b}\] enter (b)^(1/n)

jimthompson5910 (jim_thompson5910):

what did you type in?

jimthompson5910 (jim_thompson5910):

did you try 2x^2y^(17/4)

jimthompson5910 (jim_thompson5910):

I have a feeling that's what it wants

OpenStudy (anonymous):

yes i tried that. :o

jimthompson5910 (jim_thompson5910):

ok why not try 2x^2y^4y^(1/4)

OpenStudy (anonymous):

and just put the exponents in parenthesis?

jimthompson5910 (jim_thompson5910):

yeah, esp the 1/4 this is because y^1/4 means (y^1)/4 to the computer

jimthompson5910 (jim_thompson5910):

using PEMDAS, exponentiation comes first, so that explains why the computer thinks y^1/4 means (y^1)/4

OpenStudy (anonymous):

im still having trouble entering it in...

jimthompson5910 (jim_thompson5910):

the computer is just being a pain at this point hmm what else to try

OpenStudy (anonymous):

hahaha its alright! i finally got it :) i put it in "2x^2y^4(y)^(1/4)

jimthompson5910 (jim_thompson5910):

oh forgot the parenthesis around the y, i see now

OpenStudy (anonymous):

thank you so much for your help!!

jimthompson5910 (jim_thompson5910):

np

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