Events & Promotions
|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Sep 0907:00 AM PDT
-10:00 AM PDT
Meet AdComs and explore top Master’s programs - MiM, MiF, MSc, MSBA and more. - Application Fee Waivers - Free 1-Week of GMAT Club Tests: - Master's Application Toolkit - Grand Prize Giveaway- Sep 09
10:00 AM PDT
-11:00 AM PDT
Three MBA applications. Three rejections. No interview invites. A year later, Aman was admitted to Cambridge Judge, SMU, and IMD. In this episode of MBA Admit Stories, Aman shares how he rebuilt his MBA application... 
Sep 0410:00 AM EDT
-11:59 PM EDT
We’ve worked incredibly hard to build TTP into the best test prep experience possible, and it would mean a lot to us to win Newsweek’s 2026 Readers’ Choice Award for Best Test Prep. If TTP has helped you, we’d be incredibly grateful for your vote.
Sep 0812:30 AM EDT
-01:30 AM EDT
Looking for your GMAT motivation to break through the score plateau? Pragati improved her score by massive 160 points with strategic guidance and hard-work! Find out how personalized mentorship and a strong mindset can turn GMAT struggles into success.
Sep 1001:00 AM EDT
-02:00 AM EDT
Learn how Keshav, a Chartered Accountant, scored an impressive 705 on GMAT in just 30 days with GMATWhiz's expert guidance. In this video, he shares preparation tips and strategies that worked for him, including the mock, time management, and more.
Sep 1008:00 PM PDT
-09:00 PM PDT
Free- full-length test + 15 concept videos + 150+ short videos + study plan!
16 Apr 2006, 12:03
Kudos
Bookmarks
Hello,
I'm a bit worried about following
I made first the mistake to simplify as follow : x^4=x^2 by dividing by x^2. Thus, I obtained x^2=1 and solutions=1, -1.
It was false because 0 belongs to the solution.
Since then, I do X^4-X^2=0 => x2(x2-1) sol=-1,0,1
---------------------------------
I've done later the same mistake.
The pb was of that kind : x/y>1.
So I multiplied by y : x*y/y>y => x>y
It was wrong again because there was one solution missing.
The right thing to do is : x/y-1>0 =>(x-y)/y >0 sol= y>0 and x>y or y<0 and x<y.
--------------------------------
So whenever I see such equations, I never divide or multiply to simplify, but put everything on one side.
Today I had an OG11 pb to solve(144)
If (4-x)/(2+x)=x , what is the value of x^2+3x-4?
I did as I learnt and put everything on one side :
(4-x)/(2+x) - x =0 etc... and was right.
As I looked the answer of OG11, I saw that they did as following:
They multiplied both sides by (2+x), yielding 4-x=x(2+x), which is quite faster.
So I'm totally blured, since I thought it was not possible to do that way!
Are there any rule for simplifying such equations?
Thanks for your answers!
I'm a bit worried about following
I made first the mistake to simplify as follow : x^4=x^2 by dividing by x^2. Thus, I obtained x^2=1 and solutions=1, -1.
It was false because 0 belongs to the solution.
Since then, I do X^4-X^2=0 => x2(x2-1) sol=-1,0,1
---------------------------------
I've done later the same mistake.
The pb was of that kind : x/y>1.
So I multiplied by y : x*y/y>y => x>y
It was wrong again because there was one solution missing.
The right thing to do is : x/y-1>0 =>(x-y)/y >0 sol= y>0 and x>y or y<0 and x<y.
--------------------------------
So whenever I see such equations, I never divide or multiply to simplify, but put everything on one side.
Today I had an OG11 pb to solve(144)
If (4-x)/(2+x)=x , what is the value of x^2+3x-4?
I did as I learnt and put everything on one side :
(4-x)/(2+x) - x =0 etc... and was right.
As I looked the answer of OG11, I saw that they did as following:
They multiplied both sides by (2+x), yielding 4-x=x(2+x), which is quite faster.
So I'm totally blured, since I thought it was not possible to do that way!
Are there any rule for simplifying such equations?
Thanks for your answers!
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!
16 Apr 2006, 12:28
Kudos
Bookmarks
there is one excerptiong to when you can divide..
if x > 0 then you can divide.. Did the OG say X was greater than 0?
if x > 0 then you can divide.. Did the OG say X was greater than 0?
16 Apr 2006, 12:33
Kudos
Bookmarks
very good question for an important concept........
here both approaches are correct. if you have inequality, do not cancel or multiply but simply put all variables at one side then solve.....
when you have equation you can canceal/multiply as under:
(4-x)/(2+x)=x
4-x = (2+x) x
2x+x^2 -4+x = 0
x^2 +3x-4 = 0
here both approaches are correct. if you have inequality, do not cancel or multiply but simply put all variables at one side then solve.....
when you have equation you can canceal/multiply as under:
(4-x)/(2+x)=x
4-x = (2+x) x
2x+x^2 -4+x = 0
x^2 +3x-4 = 0
