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    Oh the joys of additional maths...
    I'm really confused on how to factorise cubics, they are new to me and well the teacher either didn't explain them amazingly or I zoned out.... So if this is the question, how would you factorise it?
    6x³-13x²+x+2 is divided by (x-2). The remainder is 0, so I know that (x-2) is a factor. I also know you have to do this:-
    (x-2) (6x³-13²+1) but how do I factorise the bracket with the cubic?
    Thanks for any help.. )
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    (Original post by Phoebe♥)
    Oh the joys of additional maths...
    I'm really confused on how to factorise cubics, they are new to me and well the teacher either didn't explain them amazingly or I zoned out.... So if this is the question, how would you factorise it?
    6x³-13x²+x+2 is divided by (x-2). The remainder is 0, so I know that (x-2) is a factor. I also know you have to do this:-
    (x-2) (6x³-13²+1) but how do I factorise the bracket with the cubic?
    Thanks for any help.. )
    The problem is that you've written the second line wrong, if you multiply out the brackets you will see that you do not get the original cubic

    Try long division
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    (Original post by Phoebe♥)
    Oh the joys of additional maths...
    I'm really confused on how to factorise cubics, they are new to me and well the teacher either didn't explain them amazingly or I zoned out.... So if this is the question, how would you factorise it?
    6x³-13x²+x+2 is divided by (x-2). The remainder is 0, so I know that (x-2) is a factor. I also know you have to do this:-
    (x-2) (6x³-13²+1) but how do I factorise the bracket with the cubic?
    Thanks for any help.. )
    You know one bracket (x-2) you just have to figure the rest

    (x-2)(6x^2 + ?x - 1)

    You need the 6x^2 to multiply with the x
    You need the -1 to multiply with the -2


    When you multiply -2 by 6x^2 you get -12x^2 and you will need another -1x^2

    SO the x multiplied by the ?x will give you that if ? is -1

    So you have (x-2)(6x^2 - x - 1)

    You should know how to factorise a quadratic
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    you know that (x-2) is a factor, so use the fact that:

    6x^{3}-13x^{2}+x+2=(x-2)(ax^{2}+bx+c)

    expand the right side, and equate the coefficients of like powers.
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    (Original post by Phoebe♥)
    Oh the joys of additional maths...
    I'm really confused on how to factorise cubics, they are new to me and well the teacher either didn't explain them amazingly or I zoned out.... So if this is the question, how would you factorise it?
    6x³-13x²+x+2 is divided by (x-2). The remainder is 0, so I know that (x-2) is a factor. I also know you have to do this:-
    (x-2) (6x³-13²+1) but how do I factorise the bracket with the cubic?
    Thanks for any help.. )
    divide 6x^3-13^2+1 by (x-2)

    and then you will get a quadratic which you can factorize into the form (a+x)(b+x)
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    (Original post by upthegunners)
    divide (x-2) by 6x^3-13^2+1
    No

    The other way round
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    (Original post by TenOfThem)
    No

    The other way round
    haha yea

    That's what I meant...past my bed time
 
 
 
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