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Homework Help: Can't do this question please someone help

  1. Dec 24, 2011 #1
    Can't do this question :( please someone help


    I have managed to do part(A) and the answer I've got is 22 (when S=200). However, I'm stuck at part(B) at the moment. Here's what I've done so far for (B).


    I don't know how to work out the values of S for which a square cannot be constructed. Any suggestion or advice please? Thanks!

    NB: I'm not sure whether this question is classified as "precalculus" or "calculus" so if I've posted in the wrong place please let me know :)
  2. jcsd
  3. Dec 25, 2011 #2


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    Staff: Mentor

    Re: Can't do this question :( please someone help

    I'm not sure whether I am on the right track, but ....

    Code (Text):

    S = 20a + 11(b+c) +2d
      = 20a + 10(b+c) + b + c + 2d

    So,  S - (2d + b + c) = 20a + 10(b + c)
    Which can be interpreted as being a multiple of 10.
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