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.
Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:
Join Our "Master Multi-Source Reasoning Questions by Owning the Dataset” Session! Tackling Multi-Source Reasoning (MSR) on the GMAT can be like navigating through a complex maze.
Join us for an exclusive live interview with Piyush, who achieved an impressive GMAT FE 735, securing the coveted 100th percentile! Gain invaluable insights and actionable tips to elevate your own GMAT performance. Don’t miss out!
Earning a 100th percentile score on the GMAT Focus is no easy feat. But with Target Test Prep, any score is possible. Take Ming, a TTP student who recently scored 755 (Q86/V88/DI86) on the GMAT Focus Edition.
Achieving a high GMAT score while balancing a hectic work life is challenging, but with the right strategy, it's absolutely possible. Discover the ultimate GMAT study strategy designed exclusively for working professionals.
Do RC/MSR passages scare you? e-GMAT is conducting a masterclass to help you learn – Learn effective reading strategies Tackle difficult RC & MSR with confidence Excel in timed test environment
Say I have the equation: x^2 = -2x I am tempted to simply
[#permalink]
Updated on: 25 Sep 2007, 20:07
Say I have the equation: x^2 = -2x
I am tempted to simply divide each side by x, which results in: x = -2
But I understand that to be an incomplete solution. If I simplify differently, I wind up with:
x^2 = -2x
x^2 + 2x = 0
x(x + 2) = 0
Hence x = 0, -2.
Can anyone please explain this to me conceptually? How can I avoid repeating this mistake? Should I ALWAYS try to set up exponential equations by putting 0 (zero) on one side and all other terms on the other side, i.e.
POLYNOMIAL = 0
?
Thanks,
GeoMATrace
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.
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!
Originally posted by geomatrace on 25 Sep 2007, 19:38.
Last edited by geomatrace on 25 Sep 2007, 20:07, edited 1 time in total.
Re: Say I have the equation: x^2 = -2x I am tempted to simply
[#permalink]
25 Sep 2007, 20:01
geomatrace wrote:
Say I have the equation: x^2 = -2x
I am tempted to simply divide each side by x, which results in: x = -2
But I understand that to be an incomplete solution. If I simply differently, I wind up with:
x^2 = -2x x^2 + 2x = 0 x(x + 2) = 0
Hence x = 0, -2.
Can anyone please explain this to me conceptually? How can I avoid repeating this mistake? Should I ALWAYS try to set up exponential equations by putting 0 (zero) on one side and all other terms on the other side, i.e.
POLYNOMIAL = 0
?
Thanks, GeoMATrace
Yes. u should b/c when u use the method u first showed, then ur eliminating a value of X.
Re: Say I have the equation: x^2 = -2x I am tempted to simply
[#permalink]
25 Sep 2007, 20:11
geomatrace wrote:
Say I have the equation: x^2 = -2x
I am tempted to simply divide each side by x, which results in: x = -2
But I understand that to be an incomplete solution. If I simply differently, I wind up with:
x^2 = -2x x^2 + 2x = 0 x(x + 2) = 0
Hence x = 0, -2.
Can anyone please explain this to me conceptually? How can I avoid repeating this mistake? Should I ALWAYS try to set up exponential equations by putting 0 (zero) on one side and all other terms on the other side, i.e.
POLYNOMIAL = 0
?
Thanks, GeoMATrace
In short the answer is YES, you have to equate a polynomial to a zero, by bringing all the terms to LHS. Solving by bringing all the variables in a polynomial equation to the LHS allows you to extract all the "real" roots of the equation, if they exist. Now, there are equations like x^2+1 which does not have real roots but that's besides the point.
By solving equations the way you are solving you are not guaranteed to find all the roots of the equation. Clearly from you own example, you have seen that by using your method "0" is not seen as one of the roots of the equation.
HTH
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.
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!
gmatclubot
Re: Say I have the equation: x^2 = -2x I am tempted to simply [#permalink]