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.
Apr 2610:00 AM EDT
-11:00 AM EDT
The Target Test Prep course represents a quantum leap forward in GMAT preparation, a radical reinterpretation of the way that students should study. Try before you buy with a 5-day, full-access trial of the course for FREE!
Apr 2711:00 AM EDT
-12:00 PM EDT
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors
Apr 2808:00 AM PDT
-11:00 AM PDT
Whether you are just beginning your MBA journey or fine-tuning your path to a 700+ score, GMAT Day is designed to give you a competitive edge.
16 Sep 2014, 01:28
Kudos
Bookmarks
If \(x^4 = 29x^2 - 100\), then which of the following is NOT a product of three possible values of \(x\)?
I. -50
II. 25
III. 50
A. \(I\) only
B. \(II\) only
C. \(III\) only
D. \(I\) and \(II\) only
E. \(I\) and \(III\) only
I. -50
II. 25
III. 50
A. \(I\) only
B. \(II\) only
C. \(III\) only
D. \(I\) and \(II\) only
E. \(I\) and \(III\) only
RenanBragion
GMAT 1: 760 Q48 V46
Posts: 130
Updated on: 02 Apr 2025, 16:56
Originally posted by RenanBragion on 12 Jun 2020, 03:50.
Last edited by RenanBragion on 02 Apr 2025, 16:56, edited 2 times in total.
Last edited by RenanBragion on 02 Apr 2025, 16:56, edited 2 times in total.
Kudos
Bookmarks
Great question
An alternative approach:
\(x^4 - 29x^2 + 100 = 0\)
Create a variable \( y = x^2 \)
\(x^4 - 29x^2 + 100 \)
\(y^2-29y+100 = 0\)
y = 25 or y = 4
Substitute the values of y in the equation \( y = x^2 \)
Find X:
If y = 25 then x = 5 or x = -5
If y = 4 then x = 2 or x = -2
An alternative approach:
\(x^4 - 29x^2 + 100 = 0\)
Create a variable \( y = x^2 \)
\(x^4 - 29x^2 + 100 \)
\(y^2-29y+100 = 0\)
y = 25 or y = 4
Substitute the values of y in the equation \( y = x^2 \)
Find X:
If y = 25 then x = 5 or x = -5
If y = 4 then x = 2 or x = -2
General Discussion
16 Sep 2014, 01:28
Kudos
Bookmarks
Official Solution:
If \(x^4 = 29x^2 - 100\), then which of the following is NOT a product of three possible values of \(x\)?
I. -50
II. 25
III. 50
A. \(I\) only
B. \(II\) only
C. \(III\) only
D. \(I\) and \(II\) only
E. \(I\) and \(III\) only
Rearrange and factor for \(x^2\): \((x^2-25)(x^2-4)=0\).
Thus, we find that \(x=5\), \(x=-5\), \(x=2\), or \(x=-2\).
For the given options:
I. \(-50 = 5*(-5)*2\);
III. \(50 = 5*(-5)*(-2)\);
However, 25 cannot be expressed as a product of three of these values. Thus, only 25 is NOT a product of three possible values of \(x\).
Answer: B
If \(x^4 = 29x^2 - 100\), then which of the following is NOT a product of three possible values of \(x\)?
I. -50
II. 25
III. 50
A. \(I\) only
B. \(II\) only
C. \(III\) only
D. \(I\) and \(II\) only
E. \(I\) and \(III\) only
Rearrange and factor for \(x^2\): \((x^2-25)(x^2-4)=0\).
Thus, we find that \(x=5\), \(x=-5\), \(x=2\), or \(x=-2\).
For the given options:
I. \(-50 = 5*(-5)*2\);
III. \(50 = 5*(-5)*(-2)\);
However, 25 cannot be expressed as a product of three of these values. Thus, only 25 is NOT a product of three possible values of \(x\).
Answer: B
