Is this solution of linear circuit correct ? Have I applied KCL and KVL correctly?
Since there's 1.5mA through R1, there also has to be 1.5mA through the device in series with it
Since there's 2 volts aceoss R2, there also has to be 2v across the device in parallel with it.
Since there's 2 volts across R2, 4 volts across the device in series with R1 and Vs is 8 volts, then there has to be 2 volts across R1.
With all that in mind, we can say:
and the proof is in the voltage divider.
It seems you determined that R2 is 4 kΩ. That's right. It doesn't seem that you solved for R1 though. That's also very easy.
You can go thru the general equations and solve things that way, but it's actually very easy to solve for both resistors by inspection and then one divide on a calculator.
Hint: You can see from inspection the current thru and the voltage across R1. Likewise for R2.