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• ### $450 Tuition Credit & Official CAT Packs FREE December 15, 2018 December 15, 2018 10:00 PM PST 11:00 PM PST Get the complete Official GMAT Exam Pack collection worth$100 with the 3 Month Pack ($299) • ### FREE Quant Workshop by e-GMAT! December 16, 2018 December 16, 2018 07:00 AM PST 09:00 AM PST Get personalized insights on how to achieve your Target Quant Score. # What is the value of x? (1) x^2 + x - 12 = 0 (2) x^2 < 25  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics Author Message TAGS: ### Hide Tags Math Expert Joined: 02 Sep 2009 Posts: 51218 What is the value of x? (1) x^2 + x - 12 = 0 (2) x^2 < 25 [#permalink] ### Show Tags 13 Apr 2018, 01:17 1 00:00 Difficulty: 15% (low) Question Stats: 82% (01:03) correct 18% (01:01) wrong based on 77 sessions ### HideShow timer Statistics What is the value of x? (1) x^2 + x - 12 = 0 (2) x^2 < 25 _________________ Intern Joined: 28 Apr 2014 Posts: 49 GMAT 1: 640 Q50 V25 Re: What is the value of x? (1) x^2 + x - 12 = 0 (2) x^2 < 25 [#permalink] ### Show Tags 13 Apr 2018, 01:29 IMO E St1 x=4,-3 insufficient St2 -5<x<5 insufficient Combining, no unique value of x insufficient PS Forum Moderator Status: It always seems impossible until it's done. Joined: 16 Sep 2016 Posts: 422 GMAT 1: 740 Q50 V40 Re: What is the value of x? (1) x^2 + x - 12 = 0 (2) x^2 < 25 [#permalink] ### Show Tags 13 Apr 2018, 01:30 Bunuel wrote: What is the value of x? (1) x^2 + x - 12 = 0 (2) x^2 < 25 (1) $$x^2 + x - 12 = 0$$ $$x^2 + 4x - 3x -12 = 0$$ $$(x +4) (x - 3) = 0$$ x = -4 or 3 Hence Insufficient (2) $$x^2 < 25$$ x^2 - 5^2 < 0 (x + 5)(x - 5) < 0 x = (-5,5) Hence Insuff (1) + (2) : x could be either -4 or 3. Hence insuff Hence Option (E) is our answer. Best, Gladi Intern Joined: 18 Mar 2013 Posts: 11 Concentration: Marketing, Strategy GMAT 1: 480 Q36 V20 GMAT 2: 490 Q41 V19 WE: Marketing (Other) Re: What is the value of x? (1) x^2 + x - 12 = 0 (2) x^2 < 25 [#permalink] ### Show Tags 13 Apr 2018, 11:33 Answer is E. (i) simplifying the equation, (x+4)(x-3)=0 ; x=-4 or 3 Not sufficient. (ii) X^2 <25 that implies, x=2,3,4 etc., Not sufficient. Combining (i) and (ii), still not enough data to find value of x. Not sufficient. thus, answer is E Math Revolution GMAT Instructor Joined: 16 Aug 2015 Posts: 6639 GMAT 1: 760 Q51 V42 GPA: 3.82 Re: What is the value of x? (1) x^2 + x - 12 = 0 (2) x^2 < 25 [#permalink] ### Show Tags 16 Apr 2018, 07:05 Bunuel wrote: What is the value of x? (1) x^2 + x - 12 = 0 (2) x^2 < 25 Forget conventional ways of solving math questions. For DS problems, the VA (Variable Approach) method is the quickest and easiest way to find the answer without actually solving the problem. Remember that equal numbers of variables and independent equations ensure a solution. Since we have 1 variable (x) and 0 equations, D is most likely to be the answer. So, we should consider each of the conditions on their own first. Condition 1) x^2 +x-12 = 0 ⇔ (x-3)(x+4) = 0 ⇔ x = 3 or x = -4 Since we don't have a unique solution, the condition 1) is not sufficient. Condition 2) x^2 < 25 ⇔ -5 < x < 5 Since we don't have a unique solution, the condition 2) is not sufficient. Condition 1) & 2) Since x = 3 or x = -4 from the condition 1) and -5 < x < 5 from the condition 2), we have x = 3 or x = -4. Since we don't have a unique solution, both conditions together are not sufficient. Therefore, E is the answer. If the original condition includes “1 variable”, or “2 variables and 1 equation”, or “3 variables and 2 equations” etc., one more equation is required to answer the question. If each of conditions 1) and 2) provide an additional equation, there is a 59% chance that D is the answer, a 38% chance that A or B is the answer, and a 3% chance that the answer is C or E. Thus, answer D (conditions 1) and 2), when applied separately, are sufficient to answer the question) is most likely, but there may be cases where the answer is A,B,C or E. _________________ MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only$99 for 3 month Online Course"
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Re: What is the value of x? (1) x^2 + x - 12 = 0 (2) x^2 < 25  [#permalink]

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16 Apr 2018, 07:32
Answer is E. Statements (1) and (2) TOGETHER are NOT sufficient to answer the question asked, and additional data specific to the problem are needed.
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Joined: 02 Oct 2017
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Re: What is the value of x? (1) x^2 + x - 12 = 0 (2) x^2 < 25  [#permalink]

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28 Apr 2018, 08:45
I) X= -4 or 3
Insufficient

II)x=-4 to +4
Insufficient
Combining
Multiple values so answer is E

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Re: What is the value of x? (1) x^2 + x - 12 = 0 (2) x^2 < 25  [#permalink]

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30 Apr 2018, 11:46
Bunuel wrote:
What is the value of x?

(1) x^2 + x - 12 = 0
(2) x^2 < 25

Forget conventional ways of solving math questions. For DS problems, the VA (Variable Approach) method is the quickest and easiest way to find the answer without actually solving the problem. Remember that equal numbers of variables and independent equations ensure a solution.

Since we have 1 variable (x) and 0 equations, D is most likely to be the answer. So, we should consider each of the conditions on their own first.

Condition 1)
x^2 + x - 12 = 0
⇔ (x+3)(x-4) = 0
⇔ x = -3 or x = 4

Since we don't have a unique solution, the condition 1) is not sufficient.

Condition 2)
x^2 < 25
⇔ x^2 - 25 < 0
⇔ (x+5)(x-5) < 0
⇔ -5 < x < 5

Since we don't have a unique solution, the condition 2) is not sufficient.

Conditions 1) & 2)

We have x = -3 or x = 4 from the condition 1).
We have -5 < x < 5, from the condition 2).
Even when we consider both conditions together, we have x = -3 or x = 4.

Since we don't have a unique solution, both conditions together are not sufficient.

If the original condition includes “1 variable”, or “2 variables and 1 equation”, or “3 variables and 2 equations” etc., one more equation is required to answer the question. If each of conditions 1) and 2) provide an additional equation, there is a 59% chance that D is the answer, a 38% chance that A or B is the answer, and a 3% chance that the answer is C or E. Thus, answer D (conditions 1) and 2), when applied separately, are sufficient to answer the question) is most likely, but there may be cases where the answer is A,B,C or E.
_________________

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The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
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Re: What is the value of x? (1) x^2 + x - 12 = 0 (2) x^2 < 25 &nbs [#permalink] 30 Apr 2018, 11:46
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