Find the dual of:

$(A'+B).(1+B') = A'+B$ To find the dual: interchange $+$ with $\cdot$ and interchange $0$ with $1$, keeping all variables and their complements unchanged. Dual of LHS: $(A'.B)+(0.B')$ Dual of RHS: $A'.B$ Dual: $(A'.B)+(0.B') = A'.B$ (verified with the boolean tool - both sides are equivalent, since $0.B'=0$)