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    <p>According to <a href="http://en.wikipedia.org/wiki/De_Morgan%27s_laws" rel="nofollow">Wikipedia</a>, de Morgan's Law (which to me was just a thing I knew) is </p> <p>NOT (P AND Q) = (NOT P) OR (NOT Q)</p> <p>In your question, P maps to <code>(x&gt;5)</code> and Q maps to <code>(y&gt;7)</code>. Therefore <code>!((x&gt;5)&amp;&amp;(y&gt;7))</code> is your answer. But you don't have such a one in your list. (Your teacher is sloppy if this is your real question, since only one proposed answer has double round brackets, which is a huge clue - you can rule out b because it still uses || and rule out the others for a lack of double round brackets, going straight to e.)</p> <p>If you really can't make these things stand still for you, use the sample values the question provides. (If neccessary, make some up.) <code>x&gt;5</code> is true for x=7. <code>y&gt;7</code> is false for y=5. so you have <code>!true || !false</code>, which is <code>false || true</code>, which is <code>true</code>. Evaluate each of the possible expressions and rule out the ones that don't come out to the same answer. If you're still lost, pick different sample values and repeat. One of the possible answers will keep matching, or none will so you'll go with "none of the above." That will earn you the mark even if you don't really understand why.</p> <p>As for why, it's because of the opposite behaviour of <code>&amp;&amp;</code> and <code>||</code>. The only way you get a true from <code>&amp;&amp;</code> is with true on both sides. The only way you get a false from <code>||</code> is with false on both sides. If you flip the parameters with <code>!</code>, you can flip the operator and get the opposite result.</p>
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    1. POI'm having issues with applying De Morgan's Law ... Feedback?
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    1. USKate Gregory
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    1. COThanks for answering why it works, that really helps my understanding, I found the same wiki page and thats where I came up with the consolidation theory... and yes this teacher is very sloppy. He is constantly giving me code snippits that are wrong and asking what the output is, his programs are always outputting 0, if i enter 0 into his assignments it's wrong...put in false and it's marked correct. This is my first attempt at learning a programming language so it makes it pretty fustrating since it's an online only class.
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