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Math

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The length of a rectangle is 8 cm greater than its width. Find the dimensions of the rectangle if its area is 105 cm.
How do I solve?

  • Math -

    Area = Length*Width

    Information you are given:
    Area = 105cm^2
    and
    Length = width + 8

    therefore:

    105 = (width + 8)*width
    105 = width^2 + 8*width

    105 = w^2 + 8w
    rearranging we get a quadratic:

    w^2 + 8w - 105 = 0
    w^2 - 7w +15w - 105 = 0
    w(w - 7) + 15(w - 7) = 0
    (w - 7)(w + 15) = 0
    The two possible solutions are
    width = 7 or width = -15

    Well, the width must be a positive measurement so we take the width = 7

    So the answer is:
    Width = 7
    Length = 7 + 8 = 15

    Ok,
    Hope that helps

  • Math -

    The width of a rectangle is 34 units less than its length period if x is the rectangle's length, then it's area is?

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