Prove using Prove algebraically : 1) x'′⊕ y = x⊕y' = (x⊕y)'

2) x⊕1 = x'

3) x⊕x' = 1

4) (A+B)(A'C'+C)(B'+AC') = A'B (A+B)(A′.C′+C)(B′+AC)′=A′B

I know x⊕y = xy'+x'y But how do i deal with X'⊕Y? What does that become?

And for 4) I did:

(A+B)[(X+Y)'+C] [B.(AC)']

(A+B)[(A+B)'+C] [(B.(A'+B')]

then what do I do from here?

http://i.imgur.com/CPlRB91.png[/FONT][/COLOR]

Been having trouble solving these questions of my homework. Thank You!