You can
put this solution on YOUR website!20*30=600 is trhe original garden area before the path is made. thus
(20-2x)(30-2x)=400 or 600-60x-40x+4x^2=400 or 4x^2-100x+200=0 or
x^2-25x+50=0 or using the quadratic equation we get x=22.8 & x=2.2
thus the path is 2.2 ft wide
proof (30-4.4)(20-4.4)=400 or 25.6*15.6=400 or 400=400