If two opposite sides of a square are increased by 15 meters and the other sides are decreased by 5 meters, the area of the rectangle that is formed is 69 square meters. find the area of the original square.
Let y= original side
So
A = LW
60 = (y+15)(y-13)
(y+15)(y-13) = 60
y^2 + 2y - 195 = 60
y^2 + 2y- 195 - 60 = 0
y = -17 or y= 15
Toss out the negative solution to get y= 15 as the only solution.
So the square has a side length of 15 meters.
The area of this square is 15^2 = 15*15 = 225 square meters.