Hi,
Standard Form of an Equation of an Hyperbola opening right or left is
where Pt(h,k) is a center with vertices 'a' units right and left of center.
Asymptotes passing thru the center with slope = ± b/a
foci being ± sqrt(a^2 + b^2)from center along axis of symmetry y = k

x^2/16 - y^2/25 = 1 C(0,0) Vertices: (4,0) and (-4,0)
Foci = (-6.4,0) and (6.4,0) ± sqrt(41)= ± 6.4
Asymptotes y = 5/4 and y = -5/4
