Work out the details of this hyperbola (grade12)?

There is a hyperbola x^2 - y^2 = 25. The base form of this hyperbola is x^2/a^2 - y^2/b^2 = 1. The centre in this kind of hyperbola is always (0,0) the vertices are (+ or -a,0), etc etc. It's not working in my working out so I must have a method wrong. I can do more complicated questions but for some reason as soon as a and b are presumed to be 1 as thier not there, I get it wrong. Working out please.