Question 466398
if the original square lawn had a side length of S, then the remaining grass square had a side length of S-2 (one meter removed from each end)


the new grass square is 4/5 the area of the one meter border (flower bed), whose area is 5/5 of itself
___ this means that the grass is 4/9 (4 / [4+5]) of the total area


(4/9)S^2 = (S - 2)^2 ___ 4S^2 = 9S^2 - 36 S + 36 ___ 0 = 5S^2 - 36 S + 36


factoring ___ (5S - 6)(S - 6) = 0


5S - 6 = 0 ___ S = 6/5 ___ not realistic considering the one meter border reduction


S - 6 = 0 ___ S = 6