*stopping by* - need help on a mathematical expression - exponents

[RSI]

Hey everybody... I'm stopping by for a bit, none of the math-brainer people (you know who you are... Wizkid! ) are available on ICQ, and I would like to get passed this question (I went ahead, but I want to be completely done, and understanding everything).

(25^n * 5^-3n / 125^-n)^n

Please help!

Thanks alot,

-RSI

 

[yakko]

=Mlah!

You can thank me later.

 

[GreenBeret]

Boy did I misread the problem!

starting over

(25^n * 5^-3n / 125^-n)^n

(5^2n * 5^-3n / (5^3)^(-n))^n

(5^2n * 5^(-3) / 5^(-3n))^n

(5^(2n))^n

5^(2*n^2)

 

[RSI]

Damnit yakko. :|

-RSI

 

[GreenBeret]

Any questions?

 

[Nessoldaccount]

The answer is 25^n^2...is this considered acceptable

 

[RSI]

You got a different answer from Wizkid (who's on ICQ now). :Q

-RSI
thinking

 

[sciencewhiz]

I'm not sure what your supposed to do with this problem, but I am going to reduce it.

(25^n*5^(-3n)/125^(-n))^n which equals:

(25^n*125^n/5^(3n))^n by moving negative exponents to the opposite side of fraction

(25^m*125^n/125^n)^n because 5^(3n) = 125^n (think of the underline as strikethrough because the two 125^n cancel

(25^n)^n after canceling

(25^n)^n = (25^n)^2 = 25^(2n)

completely reduced, I get 625^n

I am known for making stupid mistakes in simple math so check my work carefully.

 

[Nessoldaccount]

Whizkid and I have the same answer. 25^2 = 625. I overlooked that. Better brush up on my algebra...and I'm in Calc!

 

[GreenBeret]

OOPS! There are negative signs in there. I think I need a new monitor. This one is getting WAY too fuzzy.

 

[sciencewhiz]

Note: I am not the wizkid that he was refering to, but it is nice to know that I still remember some algebra (I'm in third semester calc)

edit: looky who showed up right below me

 

[Wizkid]

OK, here it goes...

[25^n * 5^(-3n) / 125^(-n)]^n
=[ (5^2)^n * 5^(-3n) / (5^3)^-n ]^n : make all powers base 5
=[ 5^(2n) * 5^(-3n) / 5^(-3n) ]^n : simplify internal exponents by multiplying them
=[ 5^(2n + (-3n) - (-3n) ]^n : add exponents of a common base to multiply, and subtract to divide
=[ 5^(2n) ]^n : simplify
=5^(2n*n) : multiply the exponents
=5^(2n^2) : your answer

 

[Nessoldaccount]

5^(2n^2) = 25^(n^2) = 625^n

 

[Napalm381]

Wizkid is correct.

 

[GreenBeret]

I concurr w/ wizkid after reading the problem correctly

 

[RSI]

If I have 3 over square root 2, and need to rationalize, do I multiply by square root 2 over square root 2?

 

[Yeeny]

RSI: Woosh!

 

[RSI]

Thanks!

I understand now!

-RSI

 

[Nessoldaccount]

RSi that's correct. But only fat women bitch math teachers make you do that