Operational Amplifier (Op Amp) - Simple Opamp Circuit - Negative Feedback using 20k resistors and 10k resistors and an opamp

In this circuit, the non-inverting input has 5 volts coming in, represented by 10 volts being voltage divided with two 2.2k resistors at either side of the input. No current is being drawn into the input. The negative feedback from the output will make the input voltages equal, so the inverting input will also equal 5 volts. In the circuit, there is 4 volts coming in and in series with a 10k resistor, and on the other side of the inverting input, a 20k resistor is present. With the negative feedback, 100 microamps will be flowing out across the 20k resistor causing a 2 volt drop and across the 10k resistor causing a 1 volt drop. So, from 4 volts, adding 1 volt across the 10k resistor is 5 volts (at the inverting input) and across the 20k resistor will be a 2 volt jump making the output voltage 4v + 1v + 2v = 7 volts.