Anyway, just as I promised, here's the solution to the Math problem I posted yesterday. If you've not visited my site yesterday and wish to attempt the question before looking at the solution, here's the question again.

In the diagram above, ABCD is a square. The points A, B and G are collinear. The line segments AC and DG intersect at E, and the line segments DG and BC intersect at F. Suppose that DE = 15cm, EF = 9cm, and FG = xcm. Find the value of x.


Solution: (I edited it a bit. I didn't understand the solution given by the book. By the way, if you're wondering how long I took to solve this. I took a whole 10 minutes to do it.)