Foci at (-4,0) and (4,0) means the equation is of the general form
a is the distance from the center to each end of the transverse axis (i.e., to each vertex); b is the distance from the center to each end of the conjugate axis (i.e. to each co-vertex). a and b are related by
where c is the distance from the center to each focus.
The eccentricity is c/a.
The given information is c=4 and eccentricity = 5/4.
(1) Use c and the eccentricity to find a.
(2) Use to find b.
(3) Plug the a^2 and b^2 values into the general form of the equation.