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Homework Help: Quadratic word problems

  1. Sep 11, 2004 #1
    A rectangle has an area of 60 square millimetres. If the length and width were each increased by 5 millimetres, the area would be 180 square millimetres. Find the dimensions of the original rectangle.

    Could someone please help me! I have tried everything.

    The answers are 4mm and 15mm.
     
  2. jcsd
  3. Sep 11, 2004 #2
    Let the length be x mm, and the width be y mm. What can you say about x and y? What can you say about x+5 and y+5?
     
  4. Sep 11, 2004 #3
    (x + 5) x (y + 5) = 180

    Expanding,
    xy + 5x + 5y + 25 = 180

    The value of xy is given in the question. Plug in into the equation above. The rest should be easy.
     
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