# Boolean Algebra Problem

#### GeorgeEng

Joined Nov 20, 2016
14
Hi you all !!
I am reading Charles H Roth jr book and a came across an reformation of an expression I really can not understand.
It is as follows:

f=a'(b'+d)+acd'= (a'+cd')(a+b'+d)

I really can not understand how the second part of the equation come's .
Can anyone help me on that ???

Thank you very much

#### WBahn

Joined Mar 31, 2012
26,409
Try to go from the right hand side back to the left hand side. That will often give you the insight you need to go the other way.

#### GeorgeEng

Joined Nov 20, 2016
14
Try to go from the right hand side back to the left hand side. That will often give you the insight you need to go the other way.

I did it , does not make any sense.

#### WBahn

Joined Mar 31, 2012
26,409
I did it , does not make any sense.

We can't help you see where you are going wrong if you refuse to show us where you went to begin with.

If nothing else, reduce each side to SOP form and then simply walk back from that to the right hand side.

#### Papabravo

Joined Feb 24, 2006
18,768
HINT: If you expand the right hand side there will be the logical sum (logical OR) of six terms. Two of the terms can be discarded because they are always zero. Ask yourself what is left.