Usually the Opamp circuits are analysed keeping the ideal characteristics of an oPAmp in mind.They are:
1.INfinite gain
2.Infinite input impedance
3.Infinite Bandwidth
4.ZEro Output Impedance
from the above characteristics we can put simply as:
No Current flows into or out of the input terminals
and also tat Both the input terminals will always be at same voltage level(negative feedback when applies reduces the differential input voltage to
Zero)
Keeping this in mind analyse the circuits ,simply removing the Opamp(forget it,but keep the voltages in mind).
just in ideal condition
Kareja.