LALALAA E.Math Paper 2. This time, I think more marks will be deducted (at least 5).

UCLES never fails to surprise... This question required us to find the surface area of a box (the dimensions are all in terms of x) .

After expanding and simplifying, they finally state that that equation = 500... and show that it reduces to ......
Finally, solve the equation. and find the height ... -.-