This op-amp configuration is giving me trouble
Re drawing the schematic to I can add component references etc.







simulate this circuit &ndash; Schematic created using CircuitLab

I don't recognise this as a standard circuit but its got negative feedback so will try to keep both the inverting and non-inverting inputs the same

The non-inverting input is simply \$ V_2 \$

And the inverting input:

\$ \dfrac{\dfrac{V_1}{R_3}+\dfrac{V_{out}}{R_4}}{\dfrac{1}{R_3}+\dfrac{1}{R_4}} \$

Noting all resistors are the same value and equating the 2 together we get

\$ \dfrac{\dfrac{V_1}{R}+\dfrac{V_{out}}{R}}{\dfrac{1}{R}+\dfrac{1}{R}} = V_2 \$

Solving for \$V_{out} \$

\$ \dfrac{V_1}{R} + \dfrac{V_{out}}{R} = V_2 \cdot \dfrac{2}{R} \$

\$ V_{out} = 2 \cdot V_2 - V_1\$

But as others have pointed out the circuit may be drawn incorrectly with \$ R_1 \$ in the wrong position and a differential amplifier could be what is intended.