blessed2fosteradopt Posted May 20, 2010 Share Posted May 20, 2010 Here it is: A number decreased by the total of the number and 12 = We keep getting a negative and according to the answer key it is wrong and it makes sense that it is wrong but I need it broken down step by step with a short explanation, please. Thanks! Quote Link to comment Share on other sites More sharing options...
JeneralMom Posted May 20, 2010 Share Posted May 20, 2010 What is the answer according to the answer key? Quote Link to comment Share on other sites More sharing options...
Night Elf Posted May 20, 2010 Share Posted May 20, 2010 :bigear: If the equation is x - (x +12), then the x's will always cancel out and the answer is -12. So I must be reading the word sentence incorrectly. Quote Link to comment Share on other sites More sharing options...
NicksMama-Zack's Mama Too Posted May 20, 2010 Share Posted May 20, 2010 (edited) ****PLEASE IGNORE THIS POST FROM ME***** IS THEIR AN EMOCON FOR EMBARRASSED YOU RAISED YOUR HAND IN CLASS? Here it is: A number decreased by the total of the number and 12 = We keep getting a negative and according to the answer key it is wrong and it makes sense that it is wrong but I need it broken down step by step with a short explanation, please. Thanks! A number decreased by the total of the number and 12 = number is the unknown, let's call it "n" n -(n+12) becomes n +n-12 because..... to get rid of the parentheses in a case where you have a negative/subtraction sign prior to the parentheses, you make it the opposite of whatever is in the parentheses and you get n-12. n+n-12 2n-12 Am I correct? :001_huh: Edited May 20, 2010 by NicksMama-Zack's Mama Too I can't figure out what the question is.... Quote Link to comment Share on other sites More sharing options...
Night Elf Posted May 20, 2010 Share Posted May 20, 2010 A number decreased by the total of the number and 12 = number is the unknown' date=' let's call it "n" n -(n+12) becomes n +n-12 [/quote'] Wouldn't that be n - n - 12? Quote Link to comment Share on other sites More sharing options...
Snickerdoodle Posted May 20, 2010 Share Posted May 20, 2010 (edited) :) Edited May 20, 2010 by Snickerdoodle Quote Link to comment Share on other sites More sharing options...
NicksMama-Zack's Mama Too Posted May 20, 2010 Share Posted May 20, 2010 Wouldn't that be n - n - 12? I was thinking that is was decreased by the sum of itself and 12, but now I see how I could be wrong.... Very confusing. .... Quote Link to comment Share on other sites More sharing options...
nutmeg Posted May 20, 2010 Share Posted May 20, 2010 to get rid of the parentheses in a case where you have a negative/subtraction sign prior to the parentheses' date=' you make it the opposite of whatever is in the parentheses and you get [b']n-12[/b]. What is in the parentheses is a positive N and a positive 12 (n+12) To take the opposite of them makes them each negative (-n-12) Quote Link to comment Share on other sites More sharing options...
Perry Posted May 20, 2010 Share Posted May 20, 2010 Wouldn't that be n - n - 12?:iagree: Quote Link to comment Share on other sites More sharing options...
blessed2fosteradopt Posted May 20, 2010 Author Share Posted May 20, 2010 I'm still confused. :confused: The answer is -12 but I am seeing it algebraically as 12. Quote Link to comment Share on other sites More sharing options...
NicksMama-Zack's Mama Too Posted May 20, 2010 Share Posted May 20, 2010 What is in the parentheses is a positive N and a positive 12 (n+12) To take the opposite of them makes them each negative (-n-12) You are correct, I was very incorrect. :) So, like Elf says, the n's cancel each other out (n-n = 0) and the answer should be negative 12. Quote Link to comment Share on other sites More sharing options...
Night Elf Posted May 20, 2010 Share Posted May 20, 2010 I'm still confused. :confused: The answer is -12 but I am seeing it algebraically as 12. I thought you said the answer key said it was not a negative number? Here is my thinking. If the equation does equal: A number (x) is decreased by (-) the total number (x) and (+) 12. So, x - (x + 12) Let 5 = x 5 - (5 + 12) 5 - 17 -12 Let x = 10 10 - (10 + 12) 10 - 22 -12 Decreased by usually means subtraction. And usually means addition. Quote Link to comment Share on other sites More sharing options...
nutmeg Posted May 20, 2010 Share Posted May 20, 2010 I'm still confused. :confused: The answer is -12 but I am seeing it algebraically as 12. If you ignore the parenthesis, the answer would be 12. N-(N+12) N-N+12 = 12 Following the order of operations, it is -12. I want to name my next cat Pemdas, but my girls object for some reason. :) Quote Link to comment Share on other sites More sharing options...
Cinder Posted May 20, 2010 Share Posted May 20, 2010 Here it is: A number decreased by the total of the number and 12 = We keep getting a negative and according to the answer key it is wrong and it makes sense that it is wrong but I need it broken down step by step with a short explanation, please. Thanks! A number called n Is decreased by -- something will be subtracted from it the total -- a sum of the number and 12 -- n+12 So n - (n+12) Which is the same as n + (-1)(n + 12) -- distribute/multiply the -1 across Or n + (-n -12) So n - n - 12, which equals -12 Did that help? Cinder Quote Link to comment Share on other sites More sharing options...
blessed2fosteradopt Posted May 20, 2010 Author Share Posted May 20, 2010 I thought you said the answer key said it was not a negative number? No, I wrote that the answer key said it was a negative and I was seeing it as a positive, but, guess what??? Because of you and a few others the lightbulb JUST WENT OFF!! Thank you so much. I have been going crazy with this. This is scary! If I am getting stuck now I can only imagine what the future will bring. Preschool is definitely more my speed! :D:D Thank you, ladies. You are the best! Quote Link to comment Share on other sites More sharing options...
blessed2fosteradopt Posted May 20, 2010 Author Share Posted May 20, 2010 A number called n Is decreased by -- something will be subtracted from it the total -- a sum of the number and 12 -- n+12 So n - (n+12) Which is the same as n + (-1)(n + 12) -- distribute/multiply the -1 across Or n + (-n -12) So n - n - 12, which equals -12 Did that help? Cinder Tremendously. Thank you. It just goes to show you that having (2) 3 yos and fostering a 7 month old baby has depleted my ability to think straight. :001_smile: Quote Link to comment Share on other sites More sharing options...
Night Elf Posted May 20, 2010 Share Posted May 20, 2010 I want to name my next cat Pemdas, but my girls object for some reason. :) That is a fabulous idea!! I might use that idea too. My math-loving DH will like it too. Tremendously. Thank you. It just goes to show you that having (2) 3 yos and fostering a 7 month old baby has depleted my ability to think straight. :001_smile: Oh my gosh, really? You're a super woman! :) Quote Link to comment Share on other sites More sharing options...
blessed2fosteradopt Posted May 20, 2010 Author Share Posted May 20, 2010 That is a fabulous idea!! I might use that idea too. My math-loving DH will like it too. Oh my gosh, really? You're a super woman! :) No, not really. You should see my house! :D I love PEMDAS - I hadn't heard of that before, only the whole, drawn out Please Excuse My Dear Aunt Sally. It never ceases to amaze me what I learn on these boards. Quote Link to comment Share on other sites More sharing options...
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