• odium
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    11 months ago

    Explanation: How did they get from

    x + 2 = x - 2

    to

    (x+2)(x-2)=0?

    That’s not a valid step.

    • 520@kbin.social
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      11 months ago

      To further clarify,

      (x+2)(x-2) means to take the result of X+2 and times it with the result of x-2.

      While it is common in algebra to bring the other side over, in order to simplify it, this isn’t how you’d do it.

      Here, you’d either cancel out the X (by removing it on both sides) or the -2 (by adding 2 to both sides) over to make 2=-2 or X+4=X respectively, which are both nonsense equations.

          • pendingdeletion@lemmy.world
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            11 months ago

            Not really, no… “times” is not a verb. You can multiply 2 by 2, and you can express that as “2 times 2”, but it is not correct to “times 2 by 2”.

              • pendingdeletion@lemmy.world
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                11 months ago

                Not sure what you think the relevance of a Spanish-English translation of the word “multiplying” has here… but nonetheless, you can see the correct usage of the word “multiply” versus the word “times” in my explanation above. For further clarification I would suggest a real dictionary, like Oxford, Meriam-Webster, etc.

                I’m sure plenty of people will continue to make the mistake and it will become an accepted variant, though I wouldn’t consider it to be the correct usage of the word. Similar to the word “irregardless”, it’s a word, it’s used incorrectly in place of “regardless” very often, and therefore is an accepted variant. It’s just not the correct word to use. This is why I offered you my initial correction.

                • 520@kbin.social
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                  11 months ago

                  Not sure what you think the relevance of a Spanish-English translation of the word “multiplying” has here

                  It’s a more authoritative answer than a random comment by a grammar nazi.

                  Also the dictionaries you mentioned aren’t great about including common informal language, which is what ‘times by’ is.

                  • pendingdeletion@lemmy.world
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                    11 months ago

                    Yes I’m sure those at Oxford and MW could learn a thing or two from wordreference.com’s Spanish translation, which made the same mistake you did.

                    Thanks for calling me a nazi though, during otherwise polite conversation… have a good one.