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    Given that for all values of x
    (4x + a)(x – 2) ≡ (2x + 1)2 + b
    find the value of a and the value of b.

    The 2 at the end of "(2x + 1)2" is meant to be squared
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    im having a go rn
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    Expand and compare coeffiecients.
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    are you multiplying the 2+b withthe (2x+1)
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    (Original post by shamithink)
    are you multiplying the 2+b withthe (2x+1)
    No, the 2 is meant to be a squared and its just +b
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    im stuck at a dead end
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    (Original post by shamithink)
    im stuck at a dead end
    expand and simplify
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    i've got
    a=13-b all over -2
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    (Original post by shamithink)
    i've got
    a=13-b all over -2
    i meant 13+b all over -2
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    now iv got a-b= -6.5
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    (Original post by shamithink)
    im stuck at a dead end
    If you expand and simplifiy both sides you get:
    4x^2-8x+ax-2a=4x^2+4x+1+b

    So comparing, we get:
    a-8=4
    and b+1=-2a
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    (Original post by shamithink)
    now iv got a-b= -6.5
    Please don’t post answers, also this is wrong
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    (Original post by Radioactivedecay)
    If you expand and simplifiy both sides you get:
    4x^2-8x+ax-2a=4x^2+4x+1+b

    So comparing, we get:
    8-a=4
    and b+1=-2a
    You may want to check your workings on this
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    Once expanded and simplified we have the following:

    -8x ax - 2a = 4x 1 b

    Now solve for x and sub in to the right side of the equation to solve for b. I don’t know why it won’t let me put in my plus and minus signs but you should know where they go :/
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    you can do a square sign like this:

    (2x + 1){sup}2{/sup}

    but replace the { } brackets with [ ]

    (2x + 1)2
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    (Original post by Y11_Maths)
    Please don’t post answers, also this is wrong
    I knew it was wrong, i shared my solution so i could learn where i went wrong and check over my workings out
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    (Original post by Y11_Maths)
    You may want to check your workings on this
    Pretty sure its right. Why, whats wrong with it?
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    (Original post by Radioactivedecay)
    Pretty sure its right. Why, whats wrong with it?
    Check your signs
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