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    Can anyone help me o this equation. Ho do I do it??

    x+2y=9
    y=x+3
    help!!!! I can't do simultaneous equations at all
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    At just a cursory glance, x = 1, y = 4?

    Edit: Why am I getting negged? Geez, you help someone, honestly, and you get negged for it. The answer was obvious to me, if the OP understands and masters the method she'll be able to do it deductively in her mind too.
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    (Original post by fazza)
    Can anyone help me o this equation. Ho do I do it??

    x+2y=9
    y=x+3
    help!!!! I can't do simultaneous equations at all
    sub y=x+3 in the first equation and solve


    x+2(x+3)=9
    x+2x+6=9
    3x=3
    x=1

    y=1+3=4

    x=1 y=4

    job done

    why was a negged for this you abhorrent people?
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    (Original post by fazza)
    Can anyone help me o this equation. Ho do I do it??

    x+2y=9
    y=x+3
    help!!!! I can't do simultaneous equations at all
    Get both equations in terms of y...

    i.e.
    x+2y=9

    2y=9-x

    y= 4.5 -0.5x


    Since the other equation is y=x+3,

    x+3=4.5-0.5x


    Can you do the rest?
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    (Original post by fazza)
    Can anyone help me o this equation. Ho do I do it??

    x+2y=9
    y=x+3
    help!!!! I can't do simultaneous equations at all

    If you isolate x therefore x = 9 - 2y

    do the same with the second equation therefore you will have two values from the two equations for x - then try
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    Thanks so much I reckon I ca do suns like these now thanks. Xoxo
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    how i miss gcse maths.
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    (Original post by R4INBOW)
    how i miss gcse maths.
    this would have been one of the more difficult questions dawwww
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    (Original post by R4INBOW)
    how i miss gcse maths.
    I know, right?
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    (Original post by madfish)
    this would have been one of the more difficult questions dawwww
    don't you mean one of the easier questions?
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    (Original post by davros)
    don't you mean one of the easier questions?
    Agreed, I'd say vectors would be one of the hardest questions on a gcse maths paper at times
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    (Original post by davros)
    don't you mean one of the easier questions?
    would it of been? bleh i cant even remember now :L
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    (Original post by Robbie242)
    Agreed, I'd say vectors would be one of the hardest questions on a gcse maths paper at times
    they weren't on my gcse on spec
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    (Original post by R4INBOW)
    how i miss gcse maths.

    Those were the days
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    (Original post by Robbie242)
    Agreed, I'd say vectors would be one of the hardest questions on a gcse maths paper at times
    for me, at gcse level the hardest thing was probability and transformations
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    (Original post by madfish)
    would it of been? bleh i cant even remember now :L
    Well there are questions that make you think, and questions that just require you to follow a process.

    Yes, you have to learn the process and practise it, but when you've done that you can repeat it almost without thinking - this is one of those questions.
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    (Original post by madfish)
    for me, at gcse level the hardest thing was probability and transformations
    Probability at gcse is much easier than S1, with probability you dealt mostly with mutually exclusive events, at alevel you have conditional probability etc. And yes transformations, I didn't even find them out until C1 and they appeared on my gcse paper whilst I stared blankly at them
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    (Original post by madfish)
    sub y=x+3 in the first equation and solve


    x+2(x+3)=9
    x+2x+6=9
    3x=3
    x=1

    y=1+3=4

    x=1 y=4

    job done

    why was a negged for this you abhorrent people?
    Negged because you shouldn't give full worked solutions on the maths forum
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    (Original post by Robbie242)
    Negged because you shouldn't give full worked solutions on the maths forum
    robbie you negged me wtf? I never neg you bro!
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    (Original post by madfish)
    robbie you negged me wtf? I never neg you bro!
    No, I didn't neg you, I just said why you got negged :cool:
 
 
 
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