Ido not know what this question is asking me

So a median is the line segment joining one vertex to the midpoint of the opposite side. SO do that for all vertices, and see wehre they meet.

The restrictions are the x-values that make the denominator equal to zero. It's because you cannot divide anything by 0. It makes the equation undefined. 

So, firstly we can factor the denominator, x^2 - 64, and we get (x - 8)(x + 8).

Then, we can use the zero product property to find the x values that make the denominator equal to zero. 

x - 8 = 0     x + 8 = 0
  + 8 + 8         - 8 - 8
x = 8                 x = -8 

The restrictions are x = 8 and x = -8 OR x = ±8