I want to do that by superposition rule.
Firstly i need to short the E source and compute U0 in case of current divider formula?
So i will get u1 which is voltage loss when the voltage source is short $$ U1=6mA\cdot \frac{2R}{2R+R0}$$ Then in second case i will use only E source. Now i have to find total current in that circuit which is equal $$ It=\frac{E}{2R+R0}$$ And then i just compute U2 which is voltage loss when we have our current source open $$ U2=1mA\cdot 2kOhm$$ And my result is $$ U0=U2+U1=5V $$ Am i right?