Question

A building measuring 90m by 60m is to be built. A paved area of uniform width will surround the building. The paved area is to have an area of 9000m^2. How wide is the paved area

Answer 1

(90 + 2w) * (60 + 2w) = (90 * 60) + 9000

4 w^2 + 300 w + 5400 = 5400 + 9000

w^2 + 75 w - 9000 = 0

Answer 2

(90+2w)(60+2w)=9000
(w+37.5)*2-2306.25=0
w=10.52m