Determining the gain of a circuit with multiple op-amps
Assuming the opamps are connected such that they have (virtually) zero output impedance (i.e. they are 'proper' opamp circuits), you simply multiply the gains of all the stages to get the theoretical total gain. (Practical issues may change this, like power supply rails, output impedances that really aren't zero, etc.)
So, if the stages only have resistors then it's pretty easy.
However, if one or more stages have inductors and capacitors, you will still be multiplying the gains, but it's done in a complex frequency domain. That is, you'd be multiplying complex spectra. You can use a brute force method where you pick several important frequencies and multiply the complex gain for each to produce the overall complex gain for that frequency. Then interpolate other frequencies to estimate their gains. The more inductors and capacitors, the higher the 'order' of the amplifier chain, and therefore the more frequencies must be chosen.