Simplify. Which is equal to (12n^3 + 5n/n^5) - (8n^3 + 2n^2 - 4n/n^5) ?

I can't decide between 4n^2 - 2n + 1/n^4 or 4n^2 - 2n + 9/n^4. Please help!!!

Question

Simplify.  Which is equal to (12n^3 + 5n/n^5) - (8n^3 + 2n^2 - 4n/n^5) ?

I can't decide between 4n^2 - 2n + 1/n^4 or 4n^2 - 2n + 9/n^4. Please help!!!

cwrw238 · Answer

first distribute the - over the second parentheses
then simplify like terms

cwrw238 · Answer

so your penultimate line would be:
12n^3 - 8n^3 +5n/n^5 + 4n/n^5 - 2n^2

cwrw238 · Answer

or maybe I've  misread the question  
what does n^5 divide ?
its a bit ambiguous

anonymous · Answer

Well maybe a drawing would work better., |dw:1382372241418:dw|

cwrw238 · Answer

right - that's  better!

cwrw238 · Answer

these2 fractions  are subtracted right?

anonymous · Answer

Yes, the first one minus the second.

cwrw238 · Answer

ok  well subtract the numerators   that's 
12x^3 - 5n - (8n^3 + 2n^2 - 4n)

can you do that - remember to distribute the negative over the parentheses

anonymous · Answer

Well I have to simplify first right? So it would be 4n^3 + 5n + 2n^2 - 4n after combining 12n^3 and 8n^3. Then we have to combine 5n and 4n. That would make the equation 4n^3 + 1n + 2n^2. Then we need to make it into standard from so we just have to switch 1n and 2n^2 to get 

4n^3 + 2n^2 +1n

Right? Or am I doing it wrong?

cwrw238 · Answer

no don't simplify first  do distribution first 
so it  will become 
12x^3 - 5n - 8n^3 - 2n^2 + 4n

cwrw238 · Answer

now you can simplify

anonymous · Answer

Ok, so it's 4n^3 - 2n^2 - 1n. I get it now. Since it's subtraction it all needs to be subtracted not added like I did before. That's why I needed to distribute.

cwrw238 · Answer

do you see how I got the last expression?

cwrw238 · Answer

yes

cwrw238 · Answer

now you can take out the 'n' from numerator and denominator

anonymous · Answer

To make it: |dw:1382373189025:dw|
Is that right?

cwrw238 · Answer

yes

anonymous · Answer

So my answer is 4n^2 - 2n + 1/n^4 one right?

cwrw238 · Answer

no 
its -1 

but don't write it out like that 
because  a reader doesn't know what the n^4 is dividing  -   is it the whole expression or just the '1'?

 if its the whole expression then write in in parentheses;

(4n^2 - 2n - 1) / 4n^2

anonymous · Answer

Gotcha! Thank you so much! Not many people would take the time to explain it to me. It was really nice of you to do that. :) Thanks again!

cwrw238 · Answer

no problem 
are you happy with  the distribution of the '-' ?

anonymous · Answer

Yes, I think I've got it figured out now. :)