Question

need help on final step
A ∪ (C' ∪ B')

C = c,d,e,g,h,k

B = a,e,h,i,j,k

A = a,c,d,f,g,i

C' U B' = {a,c,d,e,g,h,i,j,k}

U= a,c,d,g,i