Question

The owner of an office building is expanding the length and width of a parking lot by the same amount. The lot currently measures 120 ft by 80 ft, and the expansion will increase its area by 4,400 ft2. By how many feet should the length of the parking lot be increased?

Answer 1

Present area = 120 * 80 = 9600 ft^2 so the new area will be 9600 + 4400 = 14000

So if increase in length = x we have

(x + 120)(x + 80) = 14,000

x^2 + 200x + 9600 - 14000 = 0

x^2 + 200x - 4400 = 0

x = 20 feet answer