Is a relation R(A,B,C) with functional dependencies {AB->C, C->B} in BCNF?
Given AB->C, C->B we can infer only that AB and AC are keys. It follows that C is not a superkey and therefore R does not satisfy BCNF.

The following is a possible decomposition that would satisfy BCNF

R1{A,B} KEY {A,B}
R2{A,C} KEY {A,C}
R3{C,B} KEY {C}