Find Vo of an op-amp circuit
I get exactly 9.90V for an ideal op-amp. There is net negative feedback because R4 &lt; R2 so it is stable.
Just equate the voltages at the two inputs and solve for V3.
What you call V+ is not just dependent on V1, it also depends on V3. V- also depends on V3, so V3 appears on both sides of the above-mentioned equation. Give it a try.