What is known:
Use the formula for the volume of a cube, given that you have a square base an term should appear. It will be easiest to introduce a new variable for the height - in my case.Code:square base.
You can now get an expression for the surface area given that it is equal to the sum of it's faces. If you draw a diagram you should be able to find the expression more easily.
You have simultaneous equations to solve now. Eliminate h as it's not being asked for and get the expression for A