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Math Help - I'm not sure about this...

  1. #1
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    I'm not sure about this...

    Can someone check this for me, please.
    Attached Thumbnails Attached Thumbnails I'm not sure about this...-set-3.8-problem-56.jpg  
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  2. #2
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    Quote Originally Posted by Alienis Back View Post
    Can someone check this for me, please.
    Stop at the middle line. The last line is wrong (as you would readily see if you expanded)
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  3. #3
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    Why? Isn't the second line a perfect square trinomial?
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  4. #4
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    Quote Originally Posted by Alienis Back View Post
    Why? Isn't the second line a perfect square trinomial?
    I hope that when you expanded (3a - 3b)^2 (as I suggested) you got 9a^2 - 18ab + 9b^2 ....

    This is obviously not the same as 3a^2 - 4ab + 3b^2.
    Last edited by mr fantastic; November 11th 2008 at 04:32 AM. Reason: Re-formatted equations using latex
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  5. #5
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    Quote Originally Posted by Alienis Back View Post
    Why? Isn't the second line a perfect square trinomial?
    ===============================================
    Alienis Back,
    2nd line is not correct.
    see my attachment.
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  6. #6
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    Ok. Last line is certainly wrong. No doubt. So, It shouldn't be further factor-able, should it? And where is your attachement, 2976math?
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  7. #7
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    simplfy.pdf
    Here we go.
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  8. #8
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    2976math, look for the clip.
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  9. #9
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    Quote Originally Posted by 2976math View Post
    simplfy.pdf
    Here we go.
    Your answer is useful in that it clearly shows why the trinomial in brackets cannot be factorised (because it's a sum of two squares). But it's not what I'd give as an answer to the original question (I'd stop at the middle line).
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  10. #10
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    Quote Originally Posted by Alienis Back View Post
    2976math, look for the clip.
    Can you see attachment?
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  11. #11
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    simplfy.pdf

    I did in hurry.
    18(a^2)(b^2) should be always there from 3rd line to 5th line.
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  12. #12
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    Thumbs up

    Yep!

    2976math, That was quite useful, but is a lot more that I expected. Quite useful but as I see it, it doesn't mean my aproach is wrong. I'll keep on studying yours anyway.

    Thanks a lot guys.
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