Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    8
    ReputationRep:
    Hi I'm really stuck on this simultaneous equation 3x+y=-4
    3x-4y=6
    I'm stuck on which method to use as there is a number of methods, any help would be much appreciated
    Offline

    10
    ReputationRep:
    See how in both equations you can see 3x, therefore i think the elimination method would be the easiest. Do you know how to do this method?
    Offline

    7
    ReputationRep:
    (Original post by El Patron555)
    Hi I'm really stuck on this simultaneous equation 3x+y=-4
    3x-4y=6
    I'm stuck on which method to use as there is a number of methods, any help would be much appreciated
    What methods do you think you should use? Any methods will work, it's just which ones would be quicker. Can you see anything that you can do really easily, relating to the x terms?
    • Thread Starter
    Offline

    8
    ReputationRep:
    (Original post by ecila21)
    What methods do you think you should use? Any methods will work, it's just which ones would be quicker. Can you see anything that you can do really easily, relating to the x terms?
    Should I times y in the first equation by 3 as in the second equation the first number is3x??
    • Thread Starter
    Offline

    8
    ReputationRep:
    (Original post by number0)
    See how in both equations you can see 3x, therefore i think the elimination method would be the easiest. Do you know how to do this method?
    Going to attempt that method now
    Offline

    8
    ReputationRep:
    1. If you times y in the first equation by 3, you must also times every other term (separated by + or -) in the equation by 3.

    2. In this case, you don't need to do that. Subtract equation 2 from equation one and see what you get. Remember you can only add or subtract like terms. Be careful with the double negative.
    • Thread Starter
    Offline

    8
    ReputationRep:
    (Original post by s.xw)
    1. If you times y in the first equation by 3, you must also times every other term (separated by + or -) in the equation by 3.

    2. In this case, you don't need to do that. Subtract equation 2 from equation one and see what you get. Remember you can only add or subtract like terms. Be careful with the double negative.
    I've just attempted this method and the got the answers Y= -2 and X= 0.666, I don't know if this right or not
    Offline

    8
    ReputationRep:
    You forgot the minus in front of 0.666 (2/3), so y = -2, x = -2/3. But other than that you are correct!
    • Thread Starter
    Offline

    8
    ReputationRep:
    (Original post by s.xw)
    You forgot the minus in front of 0.666 (2/3), so y = -2, x = -2/3. But other than that you are correct!
    Thank you for your help but when you wrote x = 2/3 are basically converting it into a fraction of something?
    Offline

    8
    ReputationRep:
    (Original post by El Patron555)
    Thank you for your help but when you wrote x = 2/3 are basically converting it into a fraction of something?
    Yes, in maths it's a good habit to leave answers in fractions where possible.
    Offline

    7
    ReputationRep:
    (Original post by El Patron555)
    I've just attempted this method and the got the answers Y= -2 and X= 0.666, I don't know if this right or not
    To check, you can always put the x value into the equation and see if you come out with the y value or vice versa.
    Offline

    4
    ReputationRep:
    Hi
    Please check the attachment. I hope methods are clear to you. please ask me if you any steps are not clear to you
    Attached Images
     
    • Thread Starter
    Offline

    8
    ReputationRep:
    (Original post by gurungg48)
    Hi
    Please check the attachment. I hope methods are clear to you. please ask me if you any steps are not clear to you
    Thank you I've figured it out now, much appreciated for the word you done to try and help me
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Did TEF Bronze Award affect your UCAS choices?
    Useful resources

    Make your revision easier

    Maths

    Maths Forum posting guidelines

    Not sure where to post? Read the updated guidelines here

    Equations

    How to use LaTex

    Writing equations the easy way

    Student revising

    Study habits of A* students

    Top tips from students who have already aced their exams

    Study Planner

    Create your own Study Planner

    Never miss a deadline again

    Polling station sign

    Thinking about a maths degree?

    Chat with other maths applicants

    Can you help? Study help unanswered threads

    Groups associated with this forum:

    View associated groups
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Quick reply
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.