Potentiometer output voltage for inverting amplifier and non-inverting
Find the Thevenin equivalent for the voltage source (the pot) and compare loading for inverting and non-inverting cases.
Note that the Thevenin resistance (as well as the voltage) is a function of pot wiper angle.
If the voltage is set exactly to 2V, the pot voltage when open should be 2.50V not 2.55, by the way.