A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

BioHazard9064

  • one year ago

Help

  • This Question is Closed
  1. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Choose the equivalent system of linear equations that will produce the same solution as the one given below. 4x - y = -11 2x + 3y = 5 A. -4x - 9y = -19 -10y = -30 B. 4x + 3y = 5 2y = -6 C.7x - 3y = -11 9x = -6 D.12x - 3y = -33 14x = -28

  2. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So then solve the first one and write down the results you get from it. Then solve the other ones until you get the same answers. Do you know how to solve systems of linear equations at all?

  3. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    no not really

  4. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Just started the unit

  5. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Here is a website to get started with them: http://www.purplemath.com/modules/systlin1.htm After you read a little and get a better understanding of them, I'll help you go through this problem.

  6. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ok i still don't fully understand

  7. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    is the answer B? because thats what I got before I just want to be sure cuz i have not done this in forever

  8. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Well then let's go over the example in your question together. \[\bf 4x - y = -11 \\2x + 3y = 5\] In my opinion, the substitution method is my favorite so let's use that one first. When we use substitution, we want to get rid of either the x or y value. We do this by making those values equal to each other. In this example, I would probably choose to get rid of the x value by multiplying the bottom half by 2. \[\bf 4x - y = -11 \\2(2x + 3y = 5)\]\[\bf 4x - y = -11 \\4x + 6y = 10\] Now we are going to subtract the bottom line from the top \[\bf ~~4x - y = -11 \\-(4x + 6y = 10)\]

  9. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ok

  10. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So what would we get from there?

  11. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    1?

  12. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Seperate the three different values. So \[\bf 4x-4x=?\\~and~\\-y-6y=?\\~and~\\-11-10=?\]

  13. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    x-y=1?

  14. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Can you solve those three things I have there? What is 4x-4x?

  15. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    x

  16. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    or does the x cancel out

  17. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    No, it would be 0. The x's cancel out.

  18. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    and y-y6 would be y or would it cancel out aswell

  19. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    -y-6y is the same as -1-6.

  20. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    -7y?

  21. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Correct. And -11-10 would be?

  22. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    -1?

  23. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    That would be if it was -11+10. -11-10=-21

  24. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ok

  25. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So what we have left is \[\bf -7y=-21\] Now solve for y

  26. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    3

  27. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Correct. So now substitute \[\bf y=3\] into the top section of the problem and solve for x

  28. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    The "top section" would be \[\bf 4x - y = -11\] by the way

  29. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    given what you showed me me so far it would be B. 4x + 3y = 5 2y = -6 am i right?

  30. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Let's please finish solving the example

  31. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ok

  32. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    4x - 3y =-11

  33. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\bf 4x-3=-11\]

  34. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ok

  35. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So then we would solve the bottom part 2x + 3y = 5

  36. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    What? Solve for x in \[\bf 4x-3=-11\]

  37. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Idk how to solve for the x in this part

  38. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\bf 3x=9\] Can you solve for x here?

  39. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    x = 3

  40. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    How about this one? \[\bf 3x-3=9\]

  41. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    4

  42. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    How about this one \[\bf 4x-3=-11\] Solve it the same way as that last one.

  43. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    -2

  44. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Correct. So now we have solved the example \[\bf x=-2\\y=3\]

  45. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ok

  46. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I suppose you could just plug those values into the options and see which ones work.

  47. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    indeed and the only one that has that Is B

  48. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Are you sure? B doesn't check out with me.

  49. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    wym?

  50. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ?

  51. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\bf 2(3) \neq -6\]

  52. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Oh i looked at b but saw the numbers different

  53. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Then would It Be C

  54. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\bf 9(-2)=-6?\]

  55. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    sorry im really tired so sorry if im not 100% in to it

  56. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I dont know really

  57. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Let's go over A \[\bf x=-2\\y=3\\~\\-4x - 9y = -19\] Plug em in and see if they work

  58. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    No it wont work

  59. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i don't know how to say this, but it does work.

  60. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    really

  61. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    8-27=-19 yes

  62. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh ok

  63. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    all I had to do was do 8-27

  64. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\bf x=-2\\y=3\\~\\-10y=-30\] Does it work?

  65. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Yes

  66. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So then A is all good. Now let's check D.

  67. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ok

  68. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\bf x=-2\\y=3\\~\\12x - 3y = -33\]

  69. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i believe that D wouldn't work

  70. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    What reason supports that belief?

  71. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Its really an educated guess

  72. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    What is the "educated" in that educated guess?

  73. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    a guess

  74. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So it's just a guess then

  75. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yes

  76. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Here's a pro-tip for turning your guesses into certainty: \[\huge Do\\\huge the\\\huge work\]

  77. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ok

  78. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\bf x=-2\\y=3\\~\\12x - 3y = -33\]

  79. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ok sorry im told I got to get off but I think its A am i right?

  80. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Well D is right too but yes, A is correct

  81. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Ok thanks alot

  82. BioHazard9064
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    have a good night

  83. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    U too, nite

  84. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.