I have a question that i can't find the answer to:

There's a given function: F=x+yz

Then i have to show that F+F'=1

I found that F'=x'y'+x'z'

therefore:

F+F'=x+yz+x'y'+x'z'

=yz+(xx')(xz')+x'y'

=yz+x'y'

i don't know how to go from here

Have i done something wrong.

Please Help.......

thanks in advance

cat