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Simple Additional Maths AQA GCSE problem Watch

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    Hey there guys, need some help

    Work out the values of a and b so that ;

     4(x-5) + 4(7x+a) = b(8x-3)

    Thanks,
    PS I need an answer for A and B :cool:
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    (Original post by user)
    Hey there guys, need some help

    Work out the values of a and b so that ;

     4(x-5) + 4(7x+a) = b(8x-3)

    Thanks,
    PS I need an answer for A and B :cool:
    Just multiply out both sides:

     4(x-5) + 4(7x+a) = b(8x-3) 



4x - 20 + 28x + 4a = 8bx - 3b



32x + 4a - 20 = 8bx - 3b

    Now look at the x terms on both sides:

     32x = 8bx

    You can work out b from this; next look at the number terms:

     4a - 20 = -3b

    Substitute in your value for b, and you'll get what a is
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    (Original post by cantstop-x)
    Just multiply out both sides:

     4(x-5) + 4(7x+a) = b(8x-3) 



4x - 20 + 28x + 4a = 8bx - 3b



32x + 4a - 20 = 8bx - 3b

    Now look at the x terms on both sides:

     32x = 8bx

    You can work out b from this; next look at the number terms:

     4a - 20 = -3b

    Substitute in your value for b, and you'll get what a is

    Thanks, but i dont understand how

     32x = 8bx

    surely 32x and 8bx are two different entititys due to there being different coefficients :/
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    (Original post by user)
    Thanks, but i dont understand how

     32x = 8bx

    surely 32x and 8bx are two different entititys due to there being different coefficients :/
    But the LHS expression is equal to the RHS expression. So the x terms must be equal. That's how I see it anyway.

    I'll see if anybody tells me if I'm doing it wrong though, it's always possible It just was the only way I could think of solving it!
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    (Original post by cantstop-x)
    But the LHS expression is equal to the RHS expression. So the x terms must be equal. That's how I see it anyway.

    LHS AND RHS..
    Surely thats Congruency, thats got nothing to do with it :/

    And i think your workings are right the answer is
    a=2
    b-4
    So you are going about it the right way i think..
    The markschweme says 32=8b :/
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    (Original post by user)
    LHS AND RHS..
    Surely thats Congruency, thats got nothing to do with it :/

    And i think your workings are right the answer is
    a=2
    b-4
    So you are going about it the right way i think..
    The markschweme says 32=8b :/
    I would have thought it has everything to do with it. You're not solving the equation, you're making it valid with particular values for a and b, so the right thing to do would be to say the LHS should be equivalent to the RHS?

    And the markscheme would say that because it's comparing the coefficients of the x terms, you don't need to write in the xs
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    BUMP!!

    Really confused, can someone please break down this problem in lehmans terms :/
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    Osma bin laden is aliveeee lets work out lhs and rhs of him.
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    You're not going to get an A* with distinction at this rate...
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    Im ****in gassed boy mans gonna get A* in additionalansj matrhs. and i rock beccuseje i go to skengeness *****es haaa dey got paper for me n i no questions !!!!
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    bob i h8 you Loooool
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    (Original post by khalidpatel)
    bob i h8 you Loooool
    Gasman
 
 
 
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