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Exponents and Roots are Killing Me (and my score)!!!!!!!!!

Problem Solving — algebra and arithmetic (GMAT Focus Edition)
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Exponents and Roots are Killing Me (and my score)!!!!!!!!!

by argoodin12 » Thu Jan 12, 2017 7:57 am
I understand the concept behind exponents and roots, even the advanced questions. I get all the DS questions right on these because I know what information I need, but somehow I get tripped up on the PS questions and am only getting about 40% of them right. Does anyone have any study suggestions besides the GMAT test prep videos that the GMAT 60 Day Study guide suggests? (Free resources please!)
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by [email protected] » Thu Jan 12, 2017 2:18 pm
Hi argoodin12,

To start, neither Exponents nor Roots are a huge category on the GMAT, so you might be getting overly concerned about two subjects when your time would be better spent on larger (more valuable) content. Since you're focused on increasing your score, before I can offer you the specific advice that you're looking for, it would help if you could provide a bit more information on how you've been studying and your goals:

Studies:
1) How long have you studied?
2) What materials have you used?
3) How have you scored on each of your CATs (including the Quant and Verbal Scaled Scores)?

Goals:
4) What is your goal score?
5) When are you planning to take the GMAT?
6) When are you planning to apply to Business School?
7) What Schools are you planning to apply to?

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by argoodin12 » Thu Jan 12, 2017 2:32 pm
Hi Rich,

To answer your questions:

Studies:
1)I'm on day 10 of the 60 Day Study Guide emails.
2)I'm using the prep material in the study guide emails (OG 2017, GMAT Prep Now Videos, OG Companion, and Math Forums questions).
3)I scored a 560 on the GMAT practice test. I'm assuming that's a CAT? Math: 32 Verbal: 35 (This was my absolute baseline score, before a single bit of studying or looking at any material).

Goals:
4)My ultimate goal is a 700 but I will be satisfied/certainly accepted with a 650.
5)I'm scheduled to take the GMAT on March 11th.
6)I'm applying to business school in April(ish). I'm also currently enrolled in beginning Accounting and Business Finance undergraduate classes this spring as pre-requisites for the MBA program. I plan to start in the fall.
7)I'm applying to the University of Mississippi. I'm a staff member there with free tuition!

I should also include that I haven't take a single math class since 2008 so I'm a bit rusty (English BA and Education MA). Most of it is coming back to me but I'm frustrated with the exponents/roots category because they can be solved so many different ways that seem contradictory to the similar question right before it.

Thanks! I hope this helps. I
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by [email protected] » Thu Jan 12, 2017 3:14 pm
Hi argoodin12,

Many Test Takers spend 3 months (or more) of consistent study time before they hit their 'peak' scores, so you might need to consider extending your study timeline. To hit your score goal in 2 months, you would need to have a solid foundation in the various math rules/formulas that the GMAT will test you on and you have to be comfortable doing 'math by hand.' Many GMATers are rusty with certain skills when they begin their studies though, so you're not alone. If you're having math issues beyond just exponents and radicals though, then you might want to pause your GMAT studies for a bit so that you can focus on honing your 'math skills.' For free math practice and help, I recommend that you set up an account at Khan Academy (www.khanacademy.org). The site is completely free and makes the learning a bit more fun and 'game-like' (as opposed to the dry academic approach taken by most books). While the site is vast, you should limit your studies to basic Arithmetic, Algebra and Geometry. After spending a little time re-building those skills, you can restart your GMAT studies.

1) What is your exact application deadline?

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by Matt@VeritasPrep » Thu May 11, 2017 8:13 pm
The good news is that exponents and roots are taught in every algebra I (and II) course out there, so there is a lot of practice material. I'd try Forgotten Algebra: it has great explanations and plenty of drills to get you up to speed. There are also loads of great web resources: Khan Academy, Purple Math, Math is Fun, etc.
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by Matt@VeritasPrep » Thu May 11, 2017 8:14 pm
Let me add a mathematical approach too:

If (x+1) * (|x| - 1) > 0, then either both (x+1) and (|x| - 1) are positive or both (x+1) and (|x| - 1) are negative.

Let's examine the first case: both are positive.
Since (x+1) > 0, we know x > -1.
Since |x| - 1 > 0, we know |x| > 1.
When |x| > 1, either x > 1 or x < -1. But we know x > -1, so x < -1 is impossible.
Hence, x > 1.

Now the second case: both are negative.
Since (x+1) < 0, we know x < -1.
Since |x| - 1 < 0, we know |x| < 1.
When |x| < 1, we know -1 < x < 1.
But we can't have both x < -1 and -1 < x < 1.
Hence the second case is impossible: we can't have both (x+1) and (|x| - 1) negative.

Hence both (x+1) and (|x| - 1) are positive, and x must be greater than 1.
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