SOLUTION: Rationalize denomiators, Assume all expressions under radicals represent positive numbers. ∛(3y^4 )/∛(6x^4 )

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Question 274581: Rationalize denomiators, Assume all expressions under radicals represent positive numbers.

∛(3y^4 )/∛(6x^4 )

Answer by Edwin McCravy(20064) About Me  (Show Source):
You can put this solution on YOUR website!
∛(3y^4 )/∛(6x^4 )

root%283%2C3y%5E4%29%2Froot%283%2C6x%5E4%29

First write all as one cube root:

root%283%2C%283y%5E4%29%2F%286x%5E4%29%29

Cancel the 3 into the 6, leaving 2 on the bottom:

root%283%2C%28y%5E4%29%2F%282x%5E4%29%29

Now we must multiply the denominator by whatever is necessary
to make it into a perfect cube.  The 2 needs to be multiplied
by red%282%2A2%29 or red%282%5E2%29 to make it become 2%5E3
which is a perfect cube. The x%5E4 needs to be multiplied by 
red%28x%5E2%29 to make it become x%5E6 which is a perfect cube.

So to make the denominator become a perfect cube, we need to
multiply it by red%282%5E2x%5E2%29.

Howver to keep from changing the value when we multiply the
denominator by something, we have to multiply the numerator
by the same quantity, so we multiply both numerator and denominator
by red%282%5E2x%5E2%29, and then

root%283%2C%28y%5E4%29%2F%282x%5E4%29%29

becomes:



root%283%2C%282%5E2x%5E2y%5E4%29%2F%282%5E3x%5E6%29%29

Now you can take the cube root in the denominator, leaving it
rationalized, that is, with no irrational radical at all. All
you do is divide the exponents by the radical index 3:

root%283%2C2%5E2x%5E2y%5E4%29%2F%282%5E1x%5E2%29

Change the 2%5E2 to 4 and erase the 1 exponent in the bottom:

root%283%2C4x%5E2y%5E4%29%2F%282x%5E2%29

There is still something left you must do.  Write y%5E4 as 
y%5E3y, and then you have:

root%283%2C4x%5E2y%5E3y%29%2F%282x%5E2%29

Now take the cube root of y%5E3 by putting a y on the
outside of the radical:

%28y%2Aroot%283%2C4x%5E2y%29%29%2F%282x%5E2%29 

Edwin