Ask your own question, for FREE!
Mathematics 18 Online
OpenStudy (unknownrandom):

I can't figure out where I'm messing up at. Pic attached.

OpenStudy (unknownrandom):

OpenStudy (nincompoop):

you want to multiply the numerator of the first expression and second expression then you want to multiply the denominator of the first and second expressions

OpenStudy (unknownrandom):

1/n^2 Is this answer right?

OpenStudy (nincompoop):

how so? show me your solution

OpenStudy (doc.brown):

Does that say?\[\frac{n^5}{n-6}\cdot\frac{n^2-6n}{n^8}\]

OpenStudy (unknownrandom):

yes

OpenStudy (doc.brown):

Not \[\frac{n^5}{n-6}=\frac{n^2-6n}{n^8}\]

OpenStudy (unknownrandom):

correct

OpenStudy (unknownrandom):

Here is my work.

OpenStudy (mathmale):

@UnknownRandom : I'd strongly suggest not doing the multiplication that you've indicated in your attachment. Here's why: You can greatly simplify this problem by dividing that n^5 into that n^8; the result will be n^5 where the denominator n^8 is now:\[\frac{ n^5 }{ n-6}*\frac{ n^2-6n }{n ^{8} }\rightarrow \frac{ 1 }{n-6 }*\frac{ n^2-6n }{ n^3 }\]

OpenStudy (mathmale):

Note that your new numerator, n^2-6n, can be factored into n(n-6).

OpenStudy (mathmale):

So now we have\[\frac{ n(n-6) }{ (n-6) n^3}\] and this reduces to \[\frac{ 1 }{ n^2 }\] This is not the fastest or best way to solve reduce this expression in n. To re-cap; you have nothing to gain from multiplying out numerator and denominator. Instead, factor numerator and denominator and cancel whatever you can. This leads to the proper answer MUCH faster.

OpenStudy (unknownrandom):

Thank you so much @mathmale !

OpenStudy (mathmale):

My great pleasure!

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!