A rectangular garden with dimensions 12 m by 8 m is surrounded by a walkway of uniform width, x. The total area of the garden and the walkway is 252 m2. Find the width of the walkway.

Question

 A rectangular garden with dimensions 12 m by 8 m is surrounded by a 

     walkway of uniform width, x. The total area of the garden and the walkway is 

     252 m2. Find the width of the walkway.

Answer 1

12 by 8 = 96

17.6 by 14.6 = 257 close to 252

width = a little less than 3.3 meters, somewhere between 3.2 and 3.3 meters

252 m^2 - 96 m^2 = 156 m^2 = area of the walkway

= 4x^2 + (2)(8)x + 2(10)x

4x^2 + 36x = 156

x^2 + 9x - 39 = 0

x= -9/2 + (1/2)sqr(81 +156) = about 3.2 = width of the walkway