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  • Oct 6, 2008, 02:41 PM
    karebear11
    Quadratic Equation
    The perimeter of a rectangle base is 300 m. the area of the base is 4400 m^2. what are the dimensions using quadratic equations.
  • Oct 6, 2008, 02:55 PM
    EuRa

    110 * 40

    You start with a rectangle, which has 2 sets of 2 equal sides. If you take only 1 side from each set, that will equal 150.

    One side will be X, and the other side will be whatever is left from 150... or 150 minus X, which looks like this:


    Code:

                                  X
                  -------------------------   
                  |                        |
                  |                        |
    (150 - X)      |                        |  (150 - X)
                  |                        |
                  |                        |
                  -------------------------

                                  X

    If you multiply those 2 sides, you get: X * (150 - X)

    Multiply through to get: 150X - X^2 :and set it equal to 4400

    4400 = 150X - X^2

    Then you either subtract 4400 from both sides, or do what I do and subtract 150X and add X^2 to both sides to get:

    X^2 - 150X + 4400 = 0 <----- This is your quadratic equation

    Then either graph it and find your zeros, or break it down:

    (X -110) (X - 40) = 0

    And set them both equal to 0.

    X = 110 , 40

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