Last visit was: 24 Apr 2026, 03:12 It is currently 24 Apr 2026, 03:12
Home
Messages
Tests
Schools
Events
Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
User avatar
alimad
User avatar
Joined: 10 Feb 2006
Last visit: 09 Jul 2014
Posts: 466
Own Kudos:
4,421
Posts: 466
Kudos: 4,421
3^x - 3^x-1 = 162, x (x - 1) = ? For some reason I'm stumped 09 Jul 2006, 12:16
Kudos
Add Kudos
Bookmarks
Bookmark this Post
3^x - 3^x-1 = 162, x (x - 1) = ?

For some reason I'm stumped on this one. Do we have an exponent rule when doing addition???

Thank!!



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Quantitative Questions Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
avatar
shahsac
avatar
Joined: 03 Jan 2006
Last visit: 10 Jul 2006
Posts: 11
Posts: 11
Kudos: 0
3^x - 3^x-1 = 162, x (x - 1) = ? For some reason I'm stumped Updated on: 09 Jul 2006, 12:41
Originally posted by shahsac on 09 Jul 2006, 12:23.
Last edited by shahsac on 09 Jul 2006, 12:41, edited 2 times in total.
Kudos
Add Kudos
Bookmarks
Bookmark this Post
alimad
3^x - 3^x-1 = 162, x (x - 1) = ?

For some reason I'm stumped on this one. Do we have an exponent rule when doing addition???

Thank!!
Show more



3^x - 3^(x-1) = 162
=> {3^(x-1)} * {3-1} = 162 (Taking 3^(x-1) term common)
=> 3^(x-1) = 162/2
=> 3^(x-1) = 81
=> 3^(x-1) = 3^4
=> x-1 = 4
=> x=5
User avatar
skandhadarshan
User avatar
Joined: 16 Apr 2006
Last visit: 21 Feb 2008
Posts: 32
Own Kudos:
5
Posts: 32
Kudos: 5
3^x - 3^x-1 = 162, x (x - 1) = ? For some reason I'm stumped 09 Jul 2006, 12:24
Kudos
Add Kudos
Bookmarks
Bookmark this Post
alimad
3^x - 3^x-1 = 162, x (x - 1) = ?

For some reason I'm stumped on this one. Do we have an exponent rule when doing addition???

Thank!!
Show more


3^x[1-1/3]=162
3^x[2/3]=162
3^x=243
x=5
x(x-1)=20
User avatar
alimad
User avatar
Joined: 10 Feb 2006
Last visit: 09 Jul 2014
Posts: 466
Own Kudos:
4,421
Posts: 466
Kudos: 4,421
3^x - 3^x-1 = 162, x (x - 1) = ? For some reason I'm stumped 09 Jul 2006, 12:39
Kudos
Add Kudos
Bookmarks
Bookmark this Post
skandhadarshan, how were you able to get the common of 1/3 ???
avatar
shahsac
avatar
Joined: 03 Jan 2006
Last visit: 10 Jul 2006
Posts: 11
Posts: 11
Kudos: 0
3^x - 3^x-1 = 162, x (x - 1) = ? For some reason I'm stumped 09 Jul 2006, 12:44
Kudos
Add Kudos
Bookmarks
Bookmark this Post
alimad
skandhadarshan, how were you able to get the common of 1/3 ???
Show more



Because he took 3^x as common term

3^(x-1) can also be written as {(3^x)/3}
So when 3^x is taken out as a common term....1/3 is left behind.......
User avatar
alimad
User avatar
Joined: 10 Feb 2006
Last visit: 09 Jul 2014
Posts: 466
Own Kudos:
4,421
Posts: 466
Kudos: 4,421
3^x - 3^x-1 = 162, x (x - 1) = ? For some reason I'm stumped 09 Jul 2006, 13:10
Kudos
Add Kudos
Bookmarks
Bookmark this Post
gotcha!! Thank you gentleman.



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Quantitative Questions Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!