the answer about be am number one child so yeah
We know, equation of ellipse is given by :

Here,
(h,k) is centre of the ellipse = (0,0).
a = major axis = 8.
b = minor axis = 4.
Putting all given value in above equation, we get :

Hence, this is the required solution.
All really need to do is pick one number. so, we will go with 6 and 87.
6 times 12 is 72 then you subtract that from $87.
That would be 15
To double check, you can use another one. 9 and 123.
9 times 12 is 108. subtract that from 123 and you get 15.
Your answer is B) $15
Hope I helped :)