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fkey3191

solving systems of equations by elimination 7x+2y=24 8x+2y=30 explain if possible

  • one year ago
  • one year ago

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  1. zonazoo
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    Just multiply the first equation by -1 and add it to the second equation... if it asks you to solve by elimination, it means you need to get rid of a variable in one of the equations...

    • one year ago
  2. zonazoo
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    so your first equations becomes -7x-2y=-24 then add that too the second 8x+2y=30 ... that will then give you 1x = 6 then just substitute back in to either equation to get y

    • one year ago
  3. zonazoo
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    8(6) + 2y = 30 2y = 30 - 48 2y = -18 y = -9

    • one year ago
  4. zonazoo
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    does that make sense?

    • one year ago
  5. OrthodoxMan
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    easy as pie. Use elimination method. 7x + 2y = 24 (1) 8x + 2y = 30 (2) Eliminate (1) and (2) 8x + 2y = 30 - 7x + 2y = 24 ------------------ x = 6 Substitute x = 6 into either (1) or (2) 8(6) + 2y = 30 2y = 30 - 48 y = -18/2 y = -9

    • one year ago
  6. OrthodoxMan
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    you can also check our answers. But with regards to the guy above me, the answer is right.

    • one year ago
  7. hba
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    @zonazoo You have provided the substitution method. @OrthodoxMan Try to interact with the user rather than providing solutions. The easy method to check your answer is to put the x and y values in the original question and check if L.H.S=R.H.S

    • one year ago
  8. OrthodoxMan
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    I get what you mean but some users learn by interpreting the solution rather than following a lesson.

    • one year ago
  9. fkey3191
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    thank yall (:

    • one year ago
  10. fkey3191
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    orthodox man helped alot

    • one year ago
  11. hba
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    @OrthodoxMan As a rule of thumb, we would prefer the askers to participate in the solution process instead of having the answerers doing all the work. thats not really our concern; we are aimed at being a study site, not a free answering service. We would rather promote learning the material as opposed to just handing over answers. This social contract is aimed at curbing people from using the site to cheat with ...

    • one year ago
  12. zonazoo
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    and look who gets the best response @hba hahaha

    • one year ago
  13. hba
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    @zonazoo You provided the wrong method. The asker wanted to do it with Elimination method.

    • one year ago
  14. whatisthequestion
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    @OrthodoxMan more than likely when you just type out the solution like that then they just go into a copy and paste format where they are not really thinking about the way it was solved. Also if you are staying with them for the entire question then they should be able to review the conversation just as they are able to review when you post just the solution

    • one year ago
  15. zonazoo
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    @hba and what method are you suggesting I did... b/c what I did was no different than the other.

    • one year ago
  16. whatisthequestion
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    @zonazoo you did elimination which is the same as addition but starts with the subtracting of one equation from the other instead, so you would not say to multiply by -1

    • one year ago
  17. OrthodoxMan
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    You're absolutely right, but this user really doesn't seem like she is doing a test at the moment. More like homework. However, I will keep it in mind for future questions.

    • one year ago
  18. OrthodoxMan
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    Thanks for the warning -.-

    • one year ago
  19. Outkast3r09
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    lol @hba : this is elimination. Substitution is the other method and that deals with solving for one variable and putting it into the other equation. Medal for @zonazoo

    • one year ago
  20. hba
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    @Outkast3r09 I remember the first method as Substituion and the second as elimination.4 years is a long time dude :)

    • one year ago
  21. whatisthequestion
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    @Outkast3r09 there are three methods for solving a system of equations 1. Substitution 2. Addition 3. Elimination I explained the difference between addition and elimination above

    • one year ago
  22. hba
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    I just checked both the methods and they are same :)

    • one year ago
  23. Outkast3r09
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    oh i can name many other ways to solve this but the most used are substitution and elimination. In differential equations you solve these using matrices.

    • one year ago
  24. whatisthequestion
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    I know my school system made sre we knew the difference between the two although it is an arbitrary difference

    • one year ago
  25. whatisthequestion
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    I meant at this level if you want to start talk about RREF and graphing and so on we will be here all day listing all the ways to solve this question

    • one year ago
  26. hba
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    @OrthodoxMan Thanks a lot for understanding.

    • one year ago
  27. Outkast3r09
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    I was talking about using a determinant but RREf works also

    • one year ago
  28. zonazoo
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    addition and elimination are basically the same thing... really the only other basic way to solve these is to graph and find the intersection... other than that you would either just eliminate/add/subtract (whatever you want to call it) or substitute.

    • one year ago
  29. Outkast3r09
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    and i think i meant linear algebra also hahaha.. differential could find all possibilities lol

    • one year ago
  30. zonazoo
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    and the matrix needs to be a square matrix to take a determinant

    • one year ago
  31. OrthodoxMan
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    Now in regards with my warning, there was no need to give me one. You were already consulting me about this matter that there was no need to take it to issuing me a warning, Warnings are only for obvious mis-behaviours. I have committed none of that..

    • one year ago
  32. whatisthequestion
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    Again I did admit that it always seemed like there wasn't really a difference between the two but I remember them calling them different names based on if we were subtracting or adding the two equations

    • one year ago
  33. zonazoo
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    but either way... i think we have all just taken this topic far beyond what it needs to... im sure we all understand what is said.

    • one year ago
  34. fkey3191
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    while yall are arguing haha who wants to answer the nest one the same way -4+9y=9 x-3y=-6

    • one year ago
  35. hba
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    @fkey3191 No one is going to answer your question,we can help you though.

    • one year ago
  36. whatisthequestion
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    @fkey3191 I am guessing that is suppose to be -4x + 9y = 9 x - 3y = -6 otherwise that is way to simple

    • one year ago
  37. fkey3191
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    not for me

    • one year ago
  38. whatisthequestion
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    Okay then do they say it has to be elimination?

    • one year ago
  39. OrthodoxMan
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    Well with respect to my warning, refer to the method I used to solve your previous one and apply your knowledge on solving systems of equations from lessons. Before i get banned, goodluck.

    • one year ago
  40. hba
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    @OrthodoxMan If you have been issued a warning and you feel like you should not be warned,go talk to a mod ( the one in purple ) .

    • one year ago
  41. fkey3191
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    yess

    • one year ago
  42. whatisthequestion
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    because one equation is already down to one variable which means you could just solve for y and sub in the answer for y into the second to solve for x . . . I do not see how this requires elimination at all.

    • one year ago
  43. whatisthequestion
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    BTW I meant way to simple to use elimination that may not have been clear originally

    • one year ago
  44. fkey3191
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    okay (:'

    • one year ago
  45. whatisthequestion
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    Well then my last thing to add before leaving is (╯°□°)╯︵ ┻━┻ Why do they want to over complicate things?

    • one year ago
  46. fkey3191
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    i know he was doing what i needed and i learn by getting the answer then solving up to that soo that guy was wrong.

    • one year ago
  47. hba
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    @fkey3191 If you learnt from the first question,why don't you imply it in the second question ?

    • one year ago
  48. fkey3191
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    because i have 8 more pages and im not a smarty pants like you...and im not trying to all of them

    • one year ago
  49. hba
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    @fkey3191 I am sorry no one is going to do your homework here.

    • one year ago
  50. fkey3191
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    take your brain and shove it up your retrice

    • one year ago
  51. fkey3191
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    butt

    • one year ago
  52. hba
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    @Callisto Please look into the matter.

    • one year ago
  53. hba
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    @fkey3191 Using inappropriate speech is not allowed here,you may be banned to do so. And as i mentioned earlier We are here to help you not provide answers

    • one year ago
  54. fkey3191
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    i said butt wow

    • one year ago
  55. hba
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    Please read the CoC-http://openstudy.com/code-of-conduct

    • one year ago
  56. fkey3191
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    bye

    • one year ago
  57. fkey3191
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    i think you can read it for me

    • one year ago
  58. Callisto
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    For asker, as always, this is a site for learning, not for answer-seeking. So, please do ask the others to do all the work for you (or give you the answer). For the ones who answer the question, we don't encourage you to give answer without the involving the asker in solving the question, since the asker may not learn and just copy your work. That's not learning. Regarding the warning, just take it as an reminder. If you don't make the same mistake again, that'd be fine. Last but the least, please mind the language used here.

    • one year ago
  59. Callisto
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    Oh, I miss one thing there. Please start a new post for a new question.

    • one year ago
  60. fkey3191
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    thats how i learn but okay.

    • one year ago
  61. OrthodoxMan
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    As i said, not everyone learns the same way. You guys impose quite a strict condition on people who cling to different methods of learning.

    • one year ago
  62. Callisto
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    Hmm.. Perhaps at least the asker can show that he/she has done something but got stuck in somewhere?

    • one year ago
  63. OrthodoxMan
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    Besides, I'm giving a full solution and not just the answer.

    • one year ago
  64. hba
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    There should be some interaction @OrthodoxMan .

    • one year ago
  65. OrthodoxMan
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    As you saw in this example, it clearly did not work. http://openstudy.com/study#/updates/50b1bc5de4b0e906b4a63903

    • one year ago
  66. Callisto
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    The keywords here are ''without the involving the asker in solving the question''

    • one year ago
  67. Callisto
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    In some cases, it might not work, but at least for solving equations, you can let the asker participating in solving the question.

    • one year ago
  68. OrthodoxMan
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    Reword your quote here, it's grammatically incorrect.

    • one year ago
  69. Callisto
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    Sorry, English is not my first language. Excuse me for my poor grammar/English. But do you get the meaning?

    • one year ago
  70. OrthodoxMan
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    Not really, I value the structure of sentences as it allows me to comprehend what you're saying. I would understand your "meaning" through verbal communication. Seems like that won't happen.

    • one year ago
  71. hba
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    '' without involving the asker in solving the question''*

    • one year ago
  72. hba
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    Now it sounds grammatically correct and i hope you understand ?

    • one year ago
  73. hba
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    If you are still having problems , Feel free to post a Question in the Open study feedback group-http://openstudy.com/study#/groups/OpenStudy%20Feedback.

    • one year ago
  74. OrthodoxMan
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    ahh that has been defined countless times in this thread. Now considering the fact I acknowledge who is asking the question and their purpose (say if they are taking a test or exam at the moment), you cannot issue a warning until it has been justified. If my claims are not justified, your goal to turn this site into a study group is not realistic. Why don't you check other threads for a 7 day time span and tell me whether people are giving answers or giving a path of way to the answer.

    • one year ago
  75. hba
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    @OrthodoxMan As i said if you have any further queries please post your questions in the Open study feedback group.

    • one year ago
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