Question 628503
We assume the tiles are square. Then 100*x*x is the area of the floor and.  100*x*x=225*(x-2)*(x-2).   100*x*x=225*(x*x-4*x+4).  -125*x*x+900*x-900=0. If we solve this as shown below we get possible solutions of 1.2 and 6. Because we must be able to subtract 2 from x, 6 is the correct solution. *[invoke quadratic "x", -125, 900, -900]