I am having troubles on how to approximate second Oder systems from higher order systems. I need to approximate the second order systems of the following:

G(s) = 50 / s^4 + 17s^3 + 81s^2 + 115s + 50

And

G(s) = 2800 / s^5 + 28s^4 + 292s^3 +1411s^2 + 3190s + 2800


Any link of how to do this would also be great.

Thank you