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.
Which is greater x or 4
[#permalink]
25 Dec 2018, 15:30
25 Dec 2018, 15:30
Expert Reply
00:00
Question Stats:
69% (00:31) correct
30% (00:27) wrong based on 92 sessions
Hide Show timer Statistics
\(\sqrt{x^2 + 39} = 8\)
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
Quantity A |
Quantity B |
x |
4 |
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
Re: Which is greater x or 4
[#permalink]
04 Jan 2019, 07:05
04 Jan 2019, 07:05
1
Carcass wrote:
\(\sqrt{x^2 + 39} = 8\)
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
Quantity A |
Quantity B |
x |
4 |
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
Given: \(\sqrt{x^2 + 39} = 8\)
Square both sides to get: \((\sqrt{x^2 + 39})^2 = 8^2\)
Simplify to get: \(x^2 + 39 = 64\)
Subtract 39 from both sides to get: \(x^2 = 25\)
Solve: x = 5 OR x = -5
Let's test each case for EXTRANEOUS ROOTS
When plug x = 5 and x = -5 into the original equation, the equation holds true.
If x = 5, then Quantity A is greater than Quantity B
If x = -5, then Quantity B is greater than Quantity A
Answer: D
Cheers,
Brent
Re: Which is greater x or 4
[#permalink]
04 Jan 2019, 19:45
04 Jan 2019, 19:45
Expert Reply
Carcass wrote:
\(\sqrt{x^2 + 39} = 8\)
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
Quantity A |
Quantity B |
x |
4 |
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
If we are looking at x^2 and no other term in x, it will surely give us two values of X, one negative and other positive..
But the value could be between 0and 4 and in that case 4 will always be greater..
So let us check the values..
\(\sqrt{x^2 + 39} = 8\)
Square both sides..
\(x^2+39=8^2=64....x^2=64-39=25\) so X can be 5 or -5..
Thus it may be less than 4 or greater than 4..
D
