arithmetic explanation

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>>8289591
Why are they taking the sqt root of 3^8x from 3^4x wtf

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>>8289598
This one too. No idea whats going on

If 5^sqrt(y) is 81.
then 1/(25^-sqrt(y)) = 5^(2*sqrt(y)) = 81^2= 6561
also if 3^8x = 3600 then 3^4x = 60, thus
(3^(x-1))^4 = 3^4x * 3^-4 = 60/81

thus the expression equals 60*81=4860

>>8289591
anon this is easy ajd the solution you posted tells you everything you need to know; we have nothing new to offer you
how about instead of making a thread that's worse than hw threads, you just put in some effort and study?

>>8289746
Dude, i know, i just cant undetstand the arithmetic

>>8289855
then study arithmetic.

>>8289600
It clearly explains the problem dude. What's wrong with you? >>8289608

>>8289598
because sqrt(x)=x^1/2
so 3^(4x)=3^(8x/2)=sqrt(3^(8x))

>>8289591
What the fuck, this is what the GRE is?

>>8289913
Math GRE

Not the general GRE math section I'm assuming.

>>8289913
desu if OP is going to take the math subject GRE and this is giving him trouble he might want to stop studying for the GRE and go back and brush up for a few months and then start specific GRE studying.

>>8290345
desu

>>8290347
WTF [math] desu [/math] is translated to desu...

>>8290350
SHIT
To
Be
Honest is translated to desu

>>8290342
even then, this is one of the easy problems
a few problems every exam are pretty difficult, those are what you should study for

>>8290351
try typing F A M

>>8290355
why?
senpai

>>8289855
>Dude, i know, i just cant undetstand the entire problem

>>8289591

Ahh, the GRE. Nothing more advanced than 10th grade Geometry but everything seems like a trick question. What's your major OP?

For the first problem review your Law of Exponents

(X^a)(X^b) = X^(a+b)
(X^a)/(X^b)=X^(a-b)
(X^(a))^b = X^(ab)

Remember those three rules. After that you want to look at the givens that they've given you and try to make all the numbers in your problem the same base as the ones in the givens. (Ex: not much we can do with 25 but we can make it 5^2). This helps us because the goal is to plug in the values we've been given.

There's not much more to it other than practicing. It might take some practice to look at 3^(4x) and realize that it's relevant because it's also (3^(8x))^1/2 which will then allow you to make your substitution.

Good luck friend!

>>8289600

Poster from above I missed this one.

For this problem be sure to "factor out" as much as you can. We know that we can pull out a 3^(32) out of both terms leaving us with (3)^4-1 = 80

We know that the only prime factor of 3^(32) will be three so we look at the 80. Just simply find the largest factor here. Helps if you use a factor tree (probably a billion youtube videos on the subject if you've forgotten) but you will see that 2 and 5 are the only prime factors in 80.

Don't sweat it brah, most of the general GRE math stuff you can master in a month or less.

>>8289855
Solve for x
Solve for y

Plug x and y into the 3rd equation to get your answer.

>>8289855
>>8289855
log both sides and use log properties to solve for x and y

>>8290404
Op here

Thank you anon

I solved for x and y but I don't get the right answer.

Can someone show what they solved for x and y?

I got x = 0.93 and y = 7.46

>>8290404
Middle rule should just be substituted with 1/X^a=X^(-a).

>>8290691
your x and y are correct, you should get 4860.