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Just for fun

  1. Paraglider profile image88
    Paragliderposted 7 years ago

    There's an obvious flaw in this. See who's first to spot it. Since the forum text doesn't support superscript, I'm using a^2 to mean a squared

    if a = b, then:

      a^2 = ab                (multiplying both sides by a)
      a^2 - b^2 = ab - b^2    (subtracting b^2)
      (a - b)(a + b) = b(a - b)   (factorising)
      (a + b) = b             (dividing through by (a-b)
       2b = b                 (because a=b) 
       2 = 1                  (dividing through by b)

    1. Sufidreamer profile image82
      Sufidreamerposted 7 years ago in reply to this

      Tough one - I was always crap at algebra. I would hazard a guess that a^2 - b^2 and ab - b^2 are both zero. Therefore the only result is 0 = 0 ?

      1. Paraglider profile image88
        Paragliderposted 7 years ago in reply to this

        Very close, but that's not quite the line that blows the whole thing up. Let's see if anyone else has a go, before I post the answer.

    2. quicksand profile image83
      quicksandposted 7 years ago in reply to this

      From the little mathematics I know ...

      2 x 0 = 0
      1 x 0 = 0

      Therefore 2=1

      smile

      By the way, Paraglider, congratulations on your 300th fan ... any moment now ...

      smile

      1. Paraglider profile image88
        Paragliderposted 7 years ago in reply to this

        I think your cut-down version is just too simple to fool anyone, but you never know!

        Thanks for the fan-observation smile

    3. mohitmisra profile image59
      mohitmisraposted 7 years ago in reply to this

      a^2 = ab                (multiplying both sides by a)
        a^2 - b^2 = ab - b^2    (subtracting b^2)
        (a - b)(a + b) = b(a - b)   (factorising)

          (o)(2)= 1(0)

      you are dividing 0 by 0

        (a + b) = b             (dividing through by (a-b)
         2b = b                 (because a=b) 
         2 = 1                  (dividing through by b)

    4. Daniel Carter profile image89
      Daniel Carterposted 7 years ago in reply to this

      Speak to me in quarter notes. I get that. This ain't no quarter note talk.
      LOL

      1. Paraglider profile image88
        Paragliderposted 7 years ago in reply to this

        You being crotchety?   wink

  2. seemorebangkok profile image59
    seemorebangkokposted 7 years ago

    This isn't fun, I have a hard time in Sudoku already smile

  3. StefanMDP profile image67
    StefanMDPposted 7 years ago

    My guess.

    The step : "dividing through by (a-b)"

    is invalid, because (a-b)=0 and x/0 = undefined

    1. Maddie Ruud profile image83
      Maddie Ruudposted 7 years ago in reply to this

      You're exactly right, because the whole premise is that a = b.

    2. ngureco profile image87
      ngurecoposted 7 years ago in reply to this

      The correct answer = StefanMDP

    3. Paraglider profile image88
      Paragliderposted 7 years ago in reply to this

      And the prize goes to -



      Exactly right. Division by zero is undefined (because the result tends towards infinity).

      But you must admit it's a neat trick!

      1. AEvans profile image70
        AEvansposted 7 years ago in reply to this

        Darn it!! I was just coming in to answer the question well it certainly was a good one..smile

  4. Teresa McGurk profile image61
    Teresa McGurkposted 7 years ago

    No, no, no:  I see the obvious flaw here -- Paraglider, it's simple: there's no chocolate in it.  Just add chocolate for a perfect equation, every time.  Next?

    1. Maddie Ruud profile image83
      Maddie Ruudposted 7 years ago in reply to this

      Priceless!

    2. profile image0
      pgrundyposted 7 years ago in reply to this

      See, that's why you are my people. smile

  5. profile image0
    C. C. Riterposted 7 years ago

    I don't see it: 2b=b

  6. aka-dj profile image79
    aka-djposted 7 years ago

    2b, or not 2b? That's the real question.
    Assuming a=b is the wrong assunption.smile

  7. Paraglider profile image88
    Paragliderposted 7 years ago

    Chocolate - sheeesh...

    women . . .   (d&r)

  8. Dame Scribe profile image60
    Dame Scribeposted 7 years ago

    Aww...congrats, Paraglider smile tis a time to celebrate. Will there be chocolate wink .... sighs

  9. quicksand profile image83
    quicksandposted 7 years ago

    Oh! I missed out on ^. I was wondering what it was. Poor focus!

  10. profile image61
    Brainbusterposted 7 years ago

    The Problem is in the Step 3, you are canceling out (a-b) both on the LHS as well as in the RHS. whereas a=b, and a-b=0, So divide by 0 error, as 0/0 is invalid operation ans will result in 0. As,
    0/0= 0*(1/0). Anything multiplied by 0 is 0.

  11. Paraglider profile image88
    Paragliderposted 7 years ago

    true - dividing by zero is still undefined, even after two months wink

    1. mohitmisra profile image59
      mohitmisraposted 7 years ago in reply to this

      lol  wink

  12. scheinandras profile image60
    scheinandrasposted 7 years ago

    I like this sort of mental exercises, however I'm crap at maths:) Could you get any easier ones:)

  13. AsherKade profile image77
    AsherKadeposted 7 years ago

    I don't see Misha in this forum....
    "(

 
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