You have approached the question very systematically and explained the steps pretty clearly. It's a good way to use algebra to formulate the equation. On the other hand, you guessed the x and x+1 values as these are pretty straightforward. What if the product is a pretty huge number? How would you approach the problem? The unit "m^2" should be read as "metre centimetre.The conversion was not clearly explained. On what basis that you get 500 x 400? Need to elaborate.