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Math Help - What am I missing here?

  1. #1
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    What am I missing here?

    Hi all, this is really bothering me... I am just not seeing how ...

    (x-a)+(x-a)(x+a) ----> (x-a)(x+a+a)

    ..... I know this is true because I have looked it up in a solution manual and my professor did this on the board. How!!!? Any help would be greatly apprieciated!

    Adam
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  2. #2
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    Quote Originally Posted by ahroogahh View Post
    Hi all, this is really bothering me... I am just not seeing how ...

    (x-a)+(x-a)(x+a) ----> (x-a)(x+a+a)

    ..... I know this is true because I have looked it up in a solution manual and my professor did this on the board. How!!!? Any help would be greatly apprieciated!

    Adam
    I think you want to say,
    (x-a)(x+a+1)

    Because you have,
    (x-a)(1)+(x-a)(x+a)

    Notice you have a common factor, (x-a), thus,

    (x-a)(1+x+a)
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  3. #3
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by ahroogahh View Post
    Hi all, this is really bothering me... I am just not seeing how ...

    (x-a)+(x-a)(x+a) ----> (x-a)(x+a+a)

    ..... I know this is true because I have looked it up in a solution manual and my professor did this on the board. How!!!? Any help would be greatly apprieciated!

    Adam

    (x-a)+(x-a)(x+a) ----> (x-a)(x+a+a) . this is not always true, are you sure it's not a typo? put a = 3 for example and expand the left hand side, you get a different answer from when you expand the right hand side with a = 3.

    the way i see to do this is to factor the common (x - a) out

    (x-a)+(x-a)(x+a) = (x - a)(1 + (x + a)) = (x - a)(x + a + 1)
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  4. #4
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    Thanks to both of you... I did typo the equation. one of the 'a' terms should have been '+1' as you both pointed out. Thanks for answering my question typo's and all.

    Adam
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