GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 19 Oct 2019, 03:46

Close

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

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

Points J(5,2) and K(-2,-5) are two vertices

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Manager
Manager
User avatar
P
Joined: 13 Aug 2015
Posts: 205
GMAT 1: 710 Q49 V38
GPA: 3.82
WE: Corporate Finance (Retail Banking)
GMAT ToolKit User Reviews Badge
Points J(5,2) and K(-2,-5) are two vertices  [#permalink]

Show Tags

New post 27 Jun 2017, 15:29
6
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

74% (02:37) correct 26% (02:26) wrong based on 69 sessions

HideShow timer Statistics

Points J(5,2) and K(-2,-5) are two vertices of an isosceles triangle. If L is the third vertex and has a y coordinate of 4, what is the x coordinate of L?

A. -5
B. -4
C. 4
D. 5
E. 6

_________________
If you like my posts, please give kudos. Help me unlock gmatclub tests.
Intern
Intern
avatar
B
Joined: 16 Feb 2017
Posts: 18
Re: Points J(5,2) and K(-2,-5) are two vertices  [#permalink]

Show Tags

New post 27 Jun 2017, 18:44
mkrishnabdrr wrote:
Points J(5,2) and K(-2,-5) are two vertices of an isosceles triangle. If L is the third vertex and has a y coordinate of 4, what is the x coordinate of L?

A. -5
B. -4
C. 4
D. 5
E. 6


In an isosceles triangle only two sides are equal.
Considering JL and KL to be equal in length, we come across at below mentioned algebric equations using distance formula.

\(\sqrt{(x-5)^2+2^2}\)= \(\sqrt{(x+2)^2+9^2}\)

Squaring on both sides

\((x-5)^2+2^2\)=\((x+2)^2+9^2\)
\(x^2+25-10x+4=x^2+4+4x+81\)

cancelling \(x^2\) on both ends

\(29-10x=85+4x\)
\(-14x=56\)
\(x=-4\)


Hope this helps!
Manager
Manager
User avatar
P
Joined: 13 Aug 2015
Posts: 205
GMAT 1: 710 Q49 V38
GPA: 3.82
WE: Corporate Finance (Retail Banking)
GMAT ToolKit User Reviews Badge
Points J(5,2) and K(-2,-5) are two vertices  [#permalink]

Show Tags

New post 27 Jun 2017, 18:54
3
GMATAspirer09 wrote:
mkrishnabdrr wrote:
Points J(5,2) and K(-2,-5) are two vertices of an isosceles triangle. If L is the third vertex and has a y coordinate of 4, what is the x coordinate of L?

A. -5
B. -4
C. 4
D. 5
E. 6


In an isosceles triangle only two sides are equal.
Considering JL and KL to be equal in length, we come across at below mentioned algebric equations using distance formula.

\(\sqrt{(x-5)^2+2^2}\)= \(\sqrt{(x+2)^2+9^2}\)

Squaring on both sides

\((x-5)^2+2^2\)=\((x+2)^2+9^2\)
\(x^2+25-10x+4=x^2+4+4x+81\)

cancelling \(x^2\) on both ends

\(29-10x=85+4x\)
\(-14x=56\)
\(x=-4\)


Hope this helps!

This problem is solvable without algebra once we identify that the points J and K are reflection on the line y=-x.
(Reflection of y=-x: (x,y)=(-y,-x)

And any point on the line y=-x will be equidistant from the points J and k.
Hence, if y coordinate =4, then x coordinate =-4

Ans is : B

_________________
If you like my posts, please give kudos. Help me unlock gmatclub tests.
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58449
Re: Points J(5,2) and K(-2,-5) are two vertices  [#permalink]

Show Tags

New post 27 Jun 2017, 21:07
1
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 13270
Re: Points J(5,2) and K(-2,-5) are two vertices  [#permalink]

Show Tags

New post 19 Feb 2019, 09:08
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Club Bot
Re: Points J(5,2) and K(-2,-5) are two vertices   [#permalink] 19 Feb 2019, 09:08
Display posts from previous: Sort by

Points J(5,2) and K(-2,-5) are two vertices

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne