The owner of an office building is expanding the length and width of a parking lot by the same amount. The lot currently measured 120ft by 80ft, and the expansion will increase its area by 4,400ft^2. By how many feet should the parking lot be increased?

Question

Chris Rivers

Mathematics

1 February, 20:51

The owner of an office building is expanding the length and width of a parking lot by the same amount. The lot currently measured 120ft by 80ft, and the expansion will increase its area by 4,400ft^2. By how many feet should the parking lot be increased?

+1

Answers (1)

Know the Answer?

Jonathan Curtis · Answer 1

20

Step-by-step explanation:

The current area is 120 (80) = 9600 and he want to expand it by 4400 so that the new area will be 9600+4400=14000

14000 = (120+x) (80+x)

14000=9600+200x+x^2

x^2+200x-4400=0

x^2-20x+220x-4400=0

x (x-20) + 220 (x-20) = 0

(x+220) (x-20) = 0, since x is an increase it must be greater than zero so

x=20ft

(120+20) (80+20) = 14000ft^2