Question

Prove following:

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

Answer 1

Using: (x + y)(x + z) = x + yz

LHS ​= (a′ + b′)(a′ + b)(a + b′)

= [a′ + b′ b](a + b′)

= (a′ + 0)(a + b′)

= a′(a + b′)

= a′ a + a′b′

= 0 + a′b′ 

= a′b′​

LHS = RHS