(3xy^-2)^2(-2x^-4y)^3 / (x^-3y^2)^-3

I tried to check problem and of course it says my answer is wrong, but I can't figure out why!

I got:

-72y^5/x^19

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- Sep 14th 2010, 07:51 PMgustahfanNot sure if I got this problem right, can someone verify?
(3xy^-2)^2(-2x^-4y)^3 / (x^-3y^2)^-3

I tried to check problem and of course it says my answer is wrong, but I can't figure out why!

I got:

-72y^5/x^19 - Sep 14th 2010, 08:05 PMundefined
Hmm I get what you get.

$\displaystyle \dfrac{(3xy^{-2})^2(-2x^{-4}y)^3}{(x^{-3}y^2)^{-3}} =(3xy^{-2})^2(-2x^{-4}y)^3(x^{-3}y^2)^3 $

$\displaystyle =(9x^2y^{-4})(-8x^{-12}y^3)(x^{-9}y^{6})=(9)(-8)x^{2-12-9}y^{-4+3+6}=\dfrac{-72y^5}{x^{19}}$

What does your book say? (Or is it that your solution is getting rejected by an automatic checker? I have not worked with those, but perhaps it has to do with typesetting or putting the answer in a form the computer will recognize.) - Sep 14th 2010, 08:08 PMEducated
$\displaystyle \dfrac{(3xy^{-2})^2 \times (-2yx^{-4})^3}{(x^{-3} \times y^2)^-3}$

Is this your equation? If it is, then $\displaystyle \frac{-72y^5}{x^{19}}$ is correct.

I don't know if you meant -2x^(-4y) or -2x^-4 * y. - Sep 14th 2010, 08:24 PMgustahfan
Thank you Undefined and Educated. Yes the way that undefined wrote it out was correct. I tried the [tex] formatting but it came out funky. I was checking it on mathway.com. And it came out with something like:

$\displaystyle 9y^2/{x^19}$.

Again thanks for the replies, I knew I was right! - Sep 14th 2010, 08:28 PMundefined
- Sep 14th 2010, 09:00 PMEducated
Best way to learn LaTeX is to read the tutorial.

LaTeX Tutorial

I find that Wolfram|Alpha is a good maths computational website. Just remember to use brackets. - Sep 15th 2010, 11:05 PMRHandford
Hi All

This is also a helpful graphical interface to LaTeX, the script output can be copied and posted to site.

It can be found here