boolean algebra

Question

which of the following boolean algebra expression is incorrect ?

a . (abc)' + bc + ac = c

b . (a+b)(a'(b'+c'))' + b'c' + a'c' = 1

c . ab + a'c + bc = ab +ac

d . ab + ac' = b

guys can anyone solve this question...

i am not finding the way how to solve this...

Answer 1

a)(abc)'+bc+ac=a'+b'+c'+bc +ac

                      =a'+ac+b'+c+bc

                      = a'+c+b'+c'+b

                      =a'+1

                      =1

so a is incorrect

b)(a+b)(a'(b'+c'))'+b'c'+a'c'=(a+b)(a+bc)+b'c'+a'c'

                                      =a+abc+ab+bc+b'c'+a'c'

                                      =a(1+bc+b)+bc+b'c'+a'c'

                                      =a+bc+b'c'+a'c'

                                       ≠1

so b is incorrect

c)ab+a'c+bc=ab+a'c (consensus theorem)

d)ab+ac'!=b

so all options seems incorrect