Hello! I'm trying to determine Vout on this amplifier and I'm having some problems with the equations,because I'm not sure if they're correct! This's the link to the amplifier: http://i75.photobucket.com/albums/i281/esmeco/Amplifier-1.jpg The equations I've got so far are these: IB=0 IA=0 V2-V3=R3xI3 V3-0=I4xR4 V4-V1=R1xI1 Vo-V4=R2xI2 I have some questions:how do I know from which way does the current flow(On the wire that is connected to Vo I've determined that current flows from right to left,and,on the top,the current flows from left to right)?Is the voltage on node V3 and V4 the same as VA and VB respectively(As Va=Vb the voltage in both points are 0 volts)? Any help on this is really appreciated! Thanks in advance!