# HELP - Logic Circuits & Boolean Algebra!Watch

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#1
(This is the same as the one on the technology board - I didn't know where to post it as I know some people do Electronics GCSE!)

HELP!!!!!!!!!!!!!!!!!!!!!!!!! I have the following truth table:

A B C M
1 1 1 0
1 1 0 0
1 0 1 0
1 0 0 1
0 1 1 1
0 1 0 0
0 0 1 1
0 0 0 0

and have to construct a Boolean expression from it and then rearrange it to use only NOT & NOR functions!

Now I got the following Boolean Expression:

A.B'.C' + A'.B.C + A'.B'.C = M

Could someone show me how to simplify it using the laws of Boolean Algebra! I've NEVER done Logic circuits before and have to learn about them in the space of a mere few hours before my practical tomorrow (and I'm supposed to be going to Kate's [F.Poste on here] bday later tonight at about 9pm).
If someone could show me a detailed explanation of how to simplify is that would be really great. I have to go now as have crew table (basically dinner for rowers) but I'll be back in an hour and I'm hoping someone here will be able to help me. THANKS
0
14 years ago
#2
(Original post by Hoofbeat)
(This is the same as the one on the technology board - I didn't know where to post it as I know some people do Electronics GCSE!)

HELP!!!!!!!!!!!!!!!!!!!!!!!!! I have the following truth table:

A B C M
1 1 1 0
1 1 0 0
1 0 1 0
1 0 0 1
0 1 1 1
0 1 0 0
0 0 1 1
0 0 0 0

and have to construct a Boolean expression from it and then rearrange it to use only NOT & NOR functions!

Now I got the following Boolean Expression:

A.B'.C' + A'.B.C + A'.B'.C = M
You can take A' and C out of the last two expressions, to give

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

Now, B + B' = 1, so this term cancels
You are now left with A.B'.C' + A'.C

at this point, the post goes onto the attached image....too dificult to write in text....

As you can see, you can use NOT gates to invert the variables, and a NOT/NOR combination in order to implement the OR functions.

Hope this helps
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