What is the missing step of her solution?

The last option can't be seen

Step-by-step explanation:

x=665.6/10.4 makes the answer 64

Step-by-step explanation:

It was given that, the ellipse has directrices at

The directrices has equation: , where is the eccentricity of the ellipse.

eqn(1)

The foci are at: (0,1) qnd (0,-1)

Also, the foci are given by:

eqn(2)

Solving equation (1) and (2) simultaneously we get;

and

We use the relation, to get:

.

The equation of the ellipse is given by:

We substitute the values to get:

Or