The equation of ellipse:

The formula of c (the distance to the foci)

<h3>Answer: c² + b² = a²</h3>
It’s 4R+7
:)))))))))))))))))))
I think the answer is 5! I hope this helps!!
- Please see the attached picture for full solution!:)
------------- HappY LearninG <3 ---------
<span>complex roots (zeros) occur in conjugate pairs __ if 7+4i is a zero, then 7-4i is also a zero
for the coefficients to be rational; any irrational zeros (sqrt(7)) must have a conjugate, so -sqrt(7) is also a zero</span>