answer verification for Superposition question
No, your answer is incorrect.

Just by inspection, the 3V of the two voltage sources in series (current source is open-circuit) is pushing 1A through a total of 3&Omega; of resistance.

Then, when you consider the current source by itself (both voltage sources shorted), its 1A gets split 2:1 between the two outer resistors, for another 2/3A through the 1&Omega; resistor.

So the total current is 5/3A, and Vx is 5/3V.