# What is the feedback factor in the inverting Op Amp?

I've got a question about feedback factor. Because I don't know how to calculate it. I've been talking with some people and they say that feedback factor here is equal -R1/R2. Which is the reverse of closed loop gain = -R2/R1.

Also I read that Feedback factor for inverting is V-/Vout. But V- is 0 V so how is it posible to have Vout*B("B" stand for feedback factor). And from it I have 0 V? Vout isn't 0 V also B is also a certain value not 0. So how does it work?

Hence it's simply $$\\dfrac{R_1}{R_1+R_2}\$$.