1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Why (NOT A)(NOT B)(C) + B = (NOT A)(C) + B [Boolean Algebra]

  1. Sep 4, 2013 #1
    1. The problem statement, all variables and given/known data
    I'm studying function simplification in boolean algebra, and I didnt understand the following step:
    (NOT A)(NOT B)(C) + B = (NOT A)(C) + B

    What happened to the NOT B?

    2. Relevant equations
    3. The attempt at a solution
  2. jcsd
  3. Sep 4, 2013 #2

    D H

    User Avatar
    Staff Emeritus
    Science Advisor

    Expand (¬A)(C) on the right hand side as (¬A)(¬B)(C)+(¬A)(B)(C) and simplify.
  4. Sep 4, 2013 #3
    Hey DH thanks for helping,

    but I still don't get it, I mean...

    I need to know whats the next step of (NOT A)(NOT B)(C) + B. In your answer, you are saying that I need to expand the right side... but in a real exercise, I wouldn't know what the right side would look like
  5. Sep 4, 2013 #4

    D H

    User Avatar
    Staff Emeritus
    Science Advisor

    On the left hand side, then.

    Expand B as B = (any boolean expression whatsoever)B + B. Here we'll use B = (¬A)(C)(B) + B. Then the left hand side becomes (¬A)(¬B)(C) + (¬A)(C)(B) + B. Combine the first two terms and simplify to yield (¬A)(C).
  6. Sep 5, 2013 #5
    Got it! Thanks
  7. Sep 7, 2013 #6


    User Avatar

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted