I kind of figured that I needed to show my work. I just have no idea how to write it out.

Well I got the M of NaOH and I have the volume of it at the second equivalence pt. I get 0.00291 moles. Since I use 2NaOH for every H2X, I get 0.001455 mole of H2X. Now I simply divide the grams of the unknown and I get 487.97 g/mol. I still don't know how to show this better.