App Academy

Boolean Algebra Pratice

Hi, I am trying to find an understanding of what the X means in the Kmap. Can anyone explain this to me or give me a link to a Youtube video Thanks a bunch.
@jbyers @bryanray

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Good morning!
Those X cells represent the “Don’t Care Condition” in the K-map. Essentially, you can treat them as 1s if they help you to make your groupings. You shouldn’t need to worry about this case for the assessment, but here is a short video that goes through an example.
I hope this is helpful for you!
Jesse

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At any section does this subject exist in the course?!

Good morning!
Thank you very much @jbyers. That helps a bunch. I don’t like not understanding everything that I’m working with so yes that helps. Have a great day. And also just to clarify, since I can consider them as 1’s then I can group them with the 1’s as well? I can also just replace them with 1’s and not write the X? Thank you for your clarification.

Hi, it came up in the Boolean practice excercise #2 and I was just trying to understand what this x meant. But Mrs. Byers posted a video link in her reply so I am going to go and look at it now. Hope this helps.

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Yes, you can group them with 1s. I would recommend keeping them as Xs on the page rather than changing them to 1s, but you can assume they act like 1s in your groupings.

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Hi @jbyers. @bryanray sorry to bother you again, however there is something else that is really confusing me with the Boolean Algebra. Okay so in the YouTube video https://youtu.be/JPufD4PEYvY
as far as the Kmaps, it was explained very simple, however, in this screen shot…

you find that all the variables are being used. I am arriving at the same answer but I am also not understanding why we are using all these variable when we don’t have to.

so for example, I answered the above question by simply selecting Row 2 as the first group, making X. Then I chose the top two 1s as a group and made which had the common variable being the Y which was 0 so I then used a NOT operator and came up with the same answer but without all the extra work. Is it necessary that I perform these same operations if I come up with the same answer?