The first looks like a controlled gain circuit (So A shouldn't figure in final analysis). I think you should be able to solve that with Kirchoff's laws.

https://en.wikipedia.org/wiki/Kirchh...s_circuit_laws. The voltage $\displaystyle V^{+} = V_{in}$ as there is no voltage drop across RS as no current is flowing through the inputs of the op amp. R1 and R2 comprise a voltage divider which you can work out the voltage drop between them from ohms law. That should give you V- and from there you should be able to calculate $\displaystyle V_{out}$ and the gain $\displaystyle \frac{V_{out}}{V_{in}}$.

The second just looks like a capacitor resistance network. From google the current formula for a capacitor is $\displaystyle I = C \frac{dV}{dt}$. I would assume the two $\displaystyle V_{dd}$ points are connected, as they are at the same potential, even though they are not drawn that way. You should be able to solve this using Kirchoff's current laws.