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    I can't seem to find any examples in any of the textbooks I have on how to answer these types of questions (ones in bold):

    1.
    a) Show that  (1+2x)^3 = 1 + 6x + 12x^2 + 8x^3
    b) Find the values of x for which  (1+2x)^3 = 1 + 8x^3


    Or "find the independent term of x in the expansion..." type of questions

    Does anyone know where I could find some examples/provide some examples or any youtube videos that may help?

    Thanks a lot!
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    b) You need to make -6x = 12x^2. Can you see why?
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    (Original post by Mr M)
    b) You need to make -6x = 12x^2. Can you see why?

    Nope sorry
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    (Original post by IgorYakov)
    Nope sorry
    Because that would make the bit from the first line that you do not want "go away"
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    (Original post by IgorYakov)
    Nope sorry
    I'm not having that. Stare at the question a bit longer and make use of the information I gave you.
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    (Original post by TenOfThem)
    Because that would make the bit from the first line that you do not want "go away"
    Oh right, how do I make that? because If I put a value for X wouldn't they turn into numbers without x?
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    (Original post by Mr M)
    I'm not having that. Stare at the question a bit longer and make use of the information I gave you.

    I thought that if we were supposed to cancel it we would need to make  -6x - 12x^2 so I wasn't too sure
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    (Original post by IgorYakov)
    I thought that if we were supposed to cancel it we would need to make  -6x - 12x^2 so I wasn't too sure
    I'm not really sure what you are saying.

    You have been asked to find out which values of x make the following true:

    1+6x+12x^2+8x^3=1+8x^3

    This means 6x+12x^2=0

    You can factorise this:

    6x(1+2x)=0

    Which leads to two solutions.
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    (Original post by Mr M)
    I'm not really sure what you are saying.

    You have been asked to find out which values of x make the following true:

    1+6x+12x^2+8x^3=1+8x^3

    This means 6x+12x^2=0

    You can factorise this:

    6x(1+2x)=0

    Which leads to two solutions.
    Aah right! I didn't think about that properly, sorry for that and thanks!!
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    (Original post by IgorYakov)
    Aah right! I didn't think about that properly, sorry for that and thanks!!
    No problem.
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    (Original post by Mr M)
    No problem.

    Sorry last thing, that would give the solutions x = 0 and x = -1/2 right? the book says x = 0 and x = 1/2 not negative, is this right?
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    (Original post by IgorYakov)
    Sorry last thing, that would give the solutions x = 0 and x = -1/2 right? the book says x = 0 and x = 1/2 not negative, is this right?
    Try substituting the answer you are unsure about into the two expressions. Does it work?
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    (Original post by Mr M)
    Try substituting the answer you are unsure about into the two expressions. Does it work?

    Aah yeah, so it is -1/2 thanks!
 
 
 
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