What’s the answer

Question

A rectangular sandbox is surrounded on all sides by a strip of grass that is 5 feet wide on all sides. The length of the sandbox is 4 feet more than the width, and the

total area for the sandbox and the grass is 189 square feet. Find the dimensions of the sandbox.

Answer 1

1.9 by 5.9 feet

L=4+W

(L+2(5))(W+2(5)) = 189

(4+W+10)(W+10) = 189

(W+14)(W+10) = 189

W^2 + 24W + 144 = 189 + 144-140

W+ 24W + 144 = 193

(W+12)^2 = 193

W+ 12 = + or - sqr193

W = sqr193-12 = about 13.9- 12 = 1.9 feet wide

L= 5.9 feet long

11.9 x 15.9 = about 189