# DeMorgan's law

#### SAYED

Joined Mar 29, 2007
14
hallo
plesae help me

apple DeMorgan's law to find the complement of the folloing expession

#### Dave

Joined Nov 17, 2003
6,969
Two points:

1. Aquaint yourself with DeMorgan's Theorums.

2. Remember that you can apply the double-NOT function such that it will not change the expression, i.e. A => NOT gives A' => NOT gives A (where ' = NOT). This is very useful when applying DeMorgan's Theorums.

Dave

#### SAYED

Joined Mar 29, 2007
14
help me I'm don't understant this subject

thank you

#### thingmaker3

Joined May 16, 2005
5,083
Did you read the information in the link? If you can cite the specific parts you are having trouble with, we can walk you through them.

#### SAYED

Joined Mar 29, 2007
14
is the ruslt right or no

#### thingmaker3

Joined May 16, 2005
5,083
Almost... you dropped an "A"

Needs to be A(B'+C') instead of simply B'+C'

Otherwise, you got it right!

Joined Mar 26, 2007
6
DEAR
you can use simple one law

( A . B )' = A' + B'

A( B. C' +(D.E)' )+ (B.F)' =

A( B. C' + D' + E' ) + B' + F' =

A . B . C' + A .D' + A .E' + B' + F'