Answering JK Flip Flop Questions: How do I get xA' + x'A + xB?

[seang]

We're analyzing JK flip flop circuits and I don't understand it.

So, Given that J = x, and K = xB' , my notes say that Q+ = JQ' + K'Q. I understand that. Then, substituting, we get xA' + x'A + xB.

I have no idea how that final result was obtained. Can anyone help me with this?

 

[berkeman]

Show and think about the circuit.

 

[waht]

K = x'B

then what's the complement of K?

K' = ?

And look up the excitation tables.