Expression of a feedback circuit

I'm modelling a feedback circuit in Ltspice, however, I want to work out the transfer function for it. See below for the circuit.Image may be NSFW.
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Now I want the form of Vfb/VOA_o as:Image may be NSFW.
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So, I've thought about breaking up the circuit into two constituents to solve for this, as follows.

Image may be NSFW.
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Would you say that this is the best way to approach this? What is the transfer function, if this is not the correct approach?