Answer:
38 feet
Explanation:
You want to know the width of a dance floor that has an area of about 2000 square feet and is 15 feet longer than wide.
Area
If w represents the width of the floor, then its length is w+15 and its area is ...
w(w+15) = 2000 . . . . . square feet
Width
Completing the square gives ...
w² +15w + 56.25 = 2056.25 . . . . . . add (15/2)² to both sides
(w +7.5)² = 2056.25 . . . . . . . . . show as a square
w +7.5 = √2056.25 . . . . . square root
w ≈ 37.846 . . . . . . . . . . subtract 7.5
The width of the dance floor is about 38 feet.
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Additional comment
The floor would be 38 ft by 53 ft, with an area of 2014 square feet.
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