# Math Question

#### Draphoelix

##### It's not the wintercold that's killing me
Can someone explain to me why (a^(-2)/b^5)^(-3) = (a^6)(b^15)

This is how far I got:

(a^(-2)/b^5)^(-3) = (b^5/(a^(-2))^3 = b^15/a^(-6) = ? What next ?

Since a^(-2) is the same as 1/a^2 you put it on the bottom, then you multiply each exponent by negative 3. This puts them both back on top.

You made an error in both your first and second transition (ironically, these errors cancel each other ).

(a^(-2)/b^5)^(-3) != (b^5/(a^(-2))^3 (counterexample: a=1, b=2)
You probably mean (a^(-2)/b^5)^(-3) = (1/((a^(-2)/b^5)))^3 = 1/((a^(-2)/b^5))^3

(b^5/(a^(-2))^3 != b^15/a^(-6) (counterexample yet again: a=1, b=2). You did the same error as last time.
The law you should be using is this: http://en.wikipedia.org/wiki/Power_(mathematics)#Negative_integer_exponents

Post here again if you're unable to solve it yourself. (assuming this is homework...)

Oww, I'm not so used at reading equations through the computer format.

Just to simplify things (my use of paranthes may be wrong)

If
1/a^2 = a^(-2)
is
1/a^(-2) = a^2 ?

___

And is b^15/a^(-6) = (a^6)(b^15)?

___

And isn't 1/((a^(-2)/b^5))^3 the same as (b^5/a^(-2))^3 ?

If
1/a^2 = a^(-2)
is
1/a^(-2) = a^2 ?
Yes. 1/a^(-2) = 1/(1/a^2) = a^2

And is b^15/a^(-6) = (a^6)(b^15)?
Yes. b^15/a^(-6) = b^15/(1/a^6) = (a^6)(b^15)

And isn't 1/((a^(-2)/b^5))^3 the same as (b^5/a^(-2))^3 ?
Yes it is. But this isn't what you wrote in your first post
I guess your error was due to a parentheses mismatch and not mathematical error ^^ I assumed you meant (b^5)/(a^(-2))^3 when you wrote (b^5/(a^(-2))^3.

Ah Sry. But thanks :thup:.

Well...I'm glad I was here to help.

General chit-chat
Help Users
• No one is chatting at the moment.
• The Helper:
https://www.thehelper.net/pages/news/ is a link to the old news portal - i will integrate it into the interface somewhere when i figure it out
• Ghan:
Need to try something
• Ghan:
Hopefully this won't cause problems.
• Ghan:
Hmm
• Ghan:
I have converted the Headline News forum to an Article type forum. It will now show the top 20 threads with more detail of each thread.
• Ghan:
See how we like that.
• The Helper:
I do not see a way to go past the 1st page of posts on the forum though
• The Helper:
It is OK though for the main page to open up on the forum in the view it was before. As long as the portal has its own URL so it can be viewed that way I do want to try it as a regular forum view for a while
• Ghan:
Yeah I'm not sure what the deal is with the pagination.
• Ghan:
It SHOULD be there so I think it might just be an artifact of having an older style.
• Ghan:
I switched it to a "Standard" article forum. This will show the thread list like normal, but the threads themselves will have the first post set up above the rest of the "comments"
• The Helper:
I don't really get that article forum but I think it is because I have never really seen it used on a multi post thread
• Ghan:
RpNation makes more use of it right now as an example: https://www.rpnation.com/news/
• The Helper:
• The Helper:
What do you think Tom?
• tom_mai78101:
I will have to get used to this.
• tom_mai78101:
The latest news feed looks good
• The Helper:
I would like to see it again like Ghan had it the first time with pagination though - without the pagination that view will not work but with pagination it just might...
• The Helper:
This drink recipe I have had more than a few times back in the day! Mind Eraser https://www.thehelper.net/threads/cocktail-mind-eraser.194720/
• The Helper:
Happy Thursday!
• Ghan:
I'm not so sure, there's still a lot of Thursday left for it to become unhappy.
+3
• The Helper:
still a few hours
• The Helper:
Its Friday!!!!
+1
• Ghan:
Thursday 7/10 would Thursday again
+3