It is currently 20 Oct 2017, 07:49

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

simultaneous and linear equations

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

Hide Tags

Intern
Intern
avatar
Joined: 21 Sep 2013
Posts: 29

Kudos [?]: 31 [0], given: 82

Location: United States
Concentration: Finance, General Management
GMAT Date: 10-25-2013
GPA: 3
WE: Operations (Mutual Funds and Brokerage)
simultaneous and linear equations [#permalink]

Show Tags

New post 28 Oct 2013, 01:23
1
This post was
BOOKMARKED
Finding values of X and Y in linear simultaneous equations can be very easy. just follow the method mentioned below.

firstly our formula to find X=numerator/denominator and Y=numerator/denominator.
ideally if we have value for any one variable we need not calculate the value for the other variable , as it can be easily substituted in the equation.

say our 2 equations are
2x+4y=10
3x+2y=11

As per our formula x= Num/deno.
now numerator is obtained by cross multiplying (4*11) and subtracting from it the cross product of (2*10)=44-20=24
and denominator is obtained by cross multiplying (4*3) and subtracting from it the cross product of (2*2)=12-4=8

therefore our value for x = Num/Den = 24/8=3


now we can find the value of Y in similar way. however, it will be time consuming . thus we just substitute the value of X in one of the variable.
2x+4y=10
2(3)+4y=10
y=1

therefore we get our two variables x=3,y=1.


hope this helps for quicker calculations.


For those who are curious how to find value of Y in a similar way the method is mentioned below.
i ll just retype the previous equations for better understanding

2x+4y=10
3x+2y=11

again for Y the same formula=Num/ Den ( but the multiplication is slightly different)
now numerator is obtained by cross multiplying (2*11) and subtracting from it the cross product of (3*10)=22-30=-8
and denominator is obtained by cross multiplying (2*2) and subtracting from it the cross product of (4*3)=4-12=-8

thus Y=num/den=-8/-8=1
y=1.

now we can find the value of X, by substituting the value of Y in any equations, as we did above.

Kudos [?]: 31 [0], given: 82

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 16634

Kudos [?]: 273 [0], given: 0

Premium Member
Re: simultaneous and linear equations [#permalink]

Show Tags

New post 14 Jul 2017, 00:52
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 Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Kudos [?]: 273 [0], given: 0

Re: simultaneous and linear equations   [#permalink] 14 Jul 2017, 00:52
Display posts from previous: Sort by

simultaneous and linear equations

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


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

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

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.