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Homework Help: Find area of a rectangle if length is given

  1. Jul 12, 2010 #1
    if the length of a rectangle = x,
    show that the area of the rectangle is given by A = 8x - x[2]
     
  2. jcsd
  3. Jul 12, 2010 #2

    CompuChip

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    Re: Algebra

    You need some more information, like that the width of the rectangle is 8 - x.
     
  4. Jul 12, 2010 #3
    Re: Algebra

    yeah thats what i thought
    the answer says

    if the length = x then the width equals 1/2 (16 - 2x) = 8 - x

    area = length x width

    a = x (8 - x )
    = 8x - x [2]

    do not understand this at all blah!
     
  5. Jul 12, 2010 #4

    CompuChip

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    Re: Algebra

    Neither do I, there must be some information you are not giving us.
    Please post the entire question.

    Other than that, let us assume for a moment that we know that the length of a rectangle is x and its width is 8 - x.
    Then do you agree that its area must be x(8 - x)?
    Do you see how opening the brackets gives 8x - x2?
     
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