Hello, I'm stuck on this question, it asks to find the voltage at node c (on the circuit below) then use this value to work out other values of the op amp circuit. I tried using kirchoff's laws but that didn't work, then I used thevenins. Basically I took out the 6k and 8k resistors and calculated the voltage difference between the two 3k resistors and got 10.5V. Then I took away the two 3k resistors and put back the 8k and 6k then using the 10.5v found the voltage drop across the 6k resistor i.e. (6k x 10.5v)/(6k + 9k) and got 4.5v. I then took 4.5 from 10.5 and got 6 volts. However I don't have answers to this question so I'm unsure if I've got the right answer and/or my method is correct, which I doubt. Any help on how to approach this question would be much appreciated.