A=LW Quadratic Equation?

[Cdobson]

The original plans for a building called for a square foundation. Changes are made in the plans that call for a rectanglar foundation whose length is 18 feet longer and whose width is 5 feet shorter than a side of the original square foundation. The area enclosed by the new foundation is 3060 ft squared. what was the length of each side of the original square foundation? (Remember area is A=LW)

 

[tkhunny]

For a Square, L = W, and it's usually called "S".

SquareArea = S*S

RectangularArea = L*W = (S+18)*(S-5) = 3060 ft^2

Now what?