GRE Prep 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.
2x2 + 6 > 40 Which values of x satisfy the inequality above?
[#permalink]
27 Oct 2018, 06:52
27 Oct 2018, 06:52
2
Expert Reply
00:00
Question Stats:
73% (00:50) correct
26% (00:58) wrong based on 120 sessions
Hide Show timer Statistics
\(2x^2 + 6 > 40\)
Which values of x satisfy the inequality above?
Indicate all such values.
A. –8
B. –6
C. –4
D. –2
E. 2
F. 4
G. 6
H. 8
Which values of x satisfy the inequality above?
Indicate all such values.
A. –8
B. –6
C. –4
D. –2
E. 2
F. 4
G. 6
H. 8
ShowHide Answer
Official Answer
A,B,G,H
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
Re: 2x2 + 6 > 40 Which values of x satisfy the inequality above?
[#permalink]
20 Dec 2019, 11:33
20 Dec 2019, 11:33
2
Carcass wrote:
\(2x^2 + 6 > 40\)
Which values of x satisfy the inequality above?
Indicate all such values.
A. –8
B. –6
C. –4
D. –2
E. 2
F. 4
G. 6
H. 8
Which values of x satisfy the inequality above?
Indicate all such values.
A. –8
B. –6
C. –4
D. –2
E. 2
F. 4
G. 6
H. 8
Given: \(2x^2 + 6 > 40\)
Subtract 6 from both sides: \(2x^2 > 34\)
Divide both sides by 2: \(x^2 > 17\)
This tells us that EITHER \(x > \sqrt{17}\) OR \(x < -\sqrt{17}\)
ASIDE: \(\sqrt{16}=4\) and \(\sqrt{25}=5\)
Since 17 is BETWEEN 16 and 25, we know that \(\sqrt{17}\) is BETWEEN 4 and 5.
So we can say, \(\sqrt{17}=\) 4.something
When we applied this to her earlier solution, we can say that EITHER x > 4.something OR x < -4.something
When we examine the answer choices we can see that -8, -6, 6 and 8 satisfy those conditions.
Answer: A, B, G, H
Cheers,
Brent
Re: 2x2 + 6 > 40 Which values of x satisfy the inequality above?
[#permalink]
02 Jul 2020, 01:01
02 Jul 2020, 01:01
2
2x^2+6>40
let's simplify to be x^2+3>20
X^2>17
This is easier to check the answers.
A -8 ==>> 64>17 good
B -6 ==> 36>17 good
C -4 ==> 16 no
D -2 ==> 4 no
the only answers are a,b,g,h
let's simplify to be x^2+3>20
X^2>17
This is easier to check the answers.
A -8 ==>> 64>17 good
B -6 ==> 36>17 good
C -4 ==> 16 no
D -2 ==> 4 no
the only answers are a,b,g,h
