The Attempt at a Solution
I know this might seem like a stupid question but are the 10/-20V voltage sources like the 5.3V or are they VDD (which is something different?) I'm also stuck on part a. If D2 is off, that means its not conducting, so zero current, but would there still be a voltage drop across it? Then since its -20V on one side does that mean V(D2)=20V gain to the node on top?