The circuit as shown above.
1. The op-amp is nonideal.
2. Both inputs have current flow, lets say 0.7 uA.
3. Only R_F is known, which is 450 KOhm.
4. Open-loop gain is high.
5. Close-loop gain needs to be around 13.
6. Initial V_in and V_out is unknown.
Question: How much voltage should be added to V_in to eliminate the impact from the non-ideal op-amp to the circuit? (So that V_in will be equal to V_in+V_x after the modification, and solve for V_x).