To get everything right it is ABSOLUTELY NECESSARY that you sketch 
the graph.  There is no other way!  You have enough information to 
sketch the graph.  The red lines are the transverse and conjugate 
axes.  The transverse axis goes between the vertices, and the
conjugate axis has its midpoint at the center.   

The center (h,k) is exactly half way between the vertex.

What point is that?

Draw the defining rectangle.  Sketch the graph like this



If you have any questions getting the equation, you can 
contact me in the message form below and I'll get back to you
by email.  There is never any charge. I just do this for fun,
and to help students.

Edwin