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adl_thoo

Since opening night, attendance at Play A has increased steadily, while attendance at Play B first rose and then fell. Equations modeling the daily attendance y at each play are shown below, where x is the number of days since opening night. On what day(s) was the attendance the same at both plays? What was the attendance? Play A: y = 15x + 76 Play B: y = –x^2 + 36x – 4

  • 11 months ago
  • 11 months ago

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  1. Luigi0210
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    You could set both equations equal to each other or graph and see where they intersect.

    • 11 months ago
  2. smokeydabear
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    Yes, all you are trying to do is find where the two graphs intersect, so setting the two equal to each other will give you the answer.

    • 11 months ago
  3. adl_thoo
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    is that my quickest way? i have 40 questions. and im only on 13.

    • 11 months ago
  4. Luigi0210
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    Yes, listen to Miss Bear :P

    • 11 months ago
  5. smokeydabear
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    Judging from your previous problems, I think your teacher is emphasizing the quadratic formula, so yes you will have to go through it once again =P

    • 11 months ago
  6. adl_thoo
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    UGH , it confuses me badly.

    • 11 months ago
  7. Luigi0210
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    I could give the solution if that'll help speed things along for you?

    • 11 months ago
  8. smokeydabear
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    It confuses you? What part of it confuses you?

    • 11 months ago
  9. adl_thoo
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    everything.

    • 11 months ago
  10. adl_thoo
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    The attendance was the same on day 5. The attendance was 151 at both plays on that day. The attendance was the same on day 16. The attendance was 316 at both plays on that day. The attendance was the same on days 5 and 16. The attendance at both plays on those days was 151 and 316 respectively. The attendance was never the same at both plays. these are my answer choices.

    • 11 months ago
  11. smokeydabear
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    It is a strategy used to figure out what value x has to be to make the quadratic equation equal to 0. Does that help?

    • 11 months ago
  12. smokeydabear
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    Honestly I am trying my hardest not to solve the problem, both for your practice and to fuel my laziness xD Luigi, would you like to solve it?

    • 11 months ago
  13. Luigi0210
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    Do you want a graph to help visual the equations?

    • 11 months ago
  14. adl_thoo
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    it doesnt matter. thats fine.

    • 11 months ago
  15. Luigi0210
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    It's kinda big sorry about the size

    • 11 months ago
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  16. smokeydabear
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    Now that you see the intersecting points, you have to realize something about this problem. This is a problem that is using months for the x axis. Tell me why there is in reality only one solution to this problem?

    • 11 months ago
  17. adl_thoo
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    okat, hmmm...

    • 11 months ago
  18. smokeydabear
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    Don't overthink it, this is more of a common sense thing. Also, you could see the reason using the attendance number as well (y axis).

    • 11 months ago
  19. Luigi0210
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    If I solved it right, and I probably didn't but the exact answer would be \[\frac{ -21+/-\sqrt{761} }{ 2}\]

    • 11 months ago
  20. Luigi0210
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    But it would be the positive answer because you can't have negative units

    • 11 months ago
  21. adl_thoo
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    would it be C? The attendance was the same on days 5 and 16. The attendance at both plays on those days was 151 and 316 respectively.

    • 11 months ago
  22. smokeydabear
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    Look at what Luigi wrote. You can't have a negative number of people, or negative number of months for that matter.

    • 11 months ago
  23. Luigi0210
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    The points of intersection is (3.2931, 125.397)

    • 11 months ago
  24. adl_thoo
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    exactly. so answer C would be correct, right?

    • 11 months ago
  25. smokeydabear
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    I may just be looking at the graph wrong, but that shouldn't be it. C is telling you that there are two solutions to this problem. What Luigi and I were trying to tell you is that there is only one valid answer here.

    • 11 months ago
  26. smokeydabear
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    Are you understanding what I'm saying?

    • 11 months ago
  27. Luigi0210
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    So what the intersection points are say is that there are 125 people on day 3

    • 11 months ago
  28. Luigi0210
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    Are you understanding this or are getting more confused? :l

    • 11 months ago
  29. adl_thoo
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    more confused.

    • 11 months ago
  30. Luigi0210
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    I'm sorry ^_^' what specifically is confusing you?

    • 11 months ago
  31. smokeydabear
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    Okay think about it like this. If you were to take exactly what the graph told you as the solutions of the problem, you would have a negative number for something that can't be negative.

    • 11 months ago
  32. adl_thoo
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    a lot. idk why i think it is C .. idk ): is it B ?

    • 11 months ago
  33. smokeydabear
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    C would make sense if you were just trying to find solutions to the raw graphs, but we are looking at a real life scenario.

    • 11 months ago
  34. adl_thoo
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    exactly... so, would it change my answer to B ?

    • 11 months ago
  35. smokeydabear
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    I feel like it's A, because the point on the graph looks more like (5, 151) than (16, 316)

    • 11 months ago
  36. Luigi0210
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    You're probably thinking of it as a general graph like bear is saying. But think of it this way. When dealing with real life, is it possible to have negative audience and/or negative days?

    • 11 months ago
  37. adl_thoo
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    no.. so, a ,, is correct?

    • 11 months ago
  38. Luigi0210
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    And what are the solution choices? I must of missed them ._.

    • 11 months ago
  39. smokeydabear
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    It was (5, 151) for A, and (16, 316) for B. C said that both are true, and D said neither are true.

    • 11 months ago
  40. adl_thoo
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    yeah, what she said . ^_*

    • 11 months ago
  41. Luigi0210
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    I'd say D.

    • 11 months ago
  42. Luigi0210
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    But yet again she is the smart one here so..

    • 11 months ago
  43. smokeydabear
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    But what is bothering me is why they would consider (16, 316) as a possible solution. It's not even the negative solution... it's not anywhere on the graph xD

    • 11 months ago
  44. smokeydabear
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    Maybe the graph is wrong...

    • 11 months ago
  45. adl_thoo
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    ahhh , im confused. @primeralph , what would your input be on this question ?

    • 11 months ago
  46. Luigi0210
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    Oops, bear is right I used the wrong equation

    • 11 months ago
  47. Luigi0210
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    it is (5, 151)

    • 11 months ago
  48. adl_thoo
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    ohh goodness. so my answer is A ?

    • 11 months ago
  49. Luigi0210
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    I'm so sorry for messing this up D:

    • 11 months ago
  50. smokeydabear
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    Oh okay, but I just plugged the B coordinates into the original equations, and it worked.

    • 11 months ago
  51. smokeydabear
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    Let me try for A next.

    • 11 months ago
  52. Luigi0210
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    I'm so sorry for messing this up D:

    • 11 months ago
  53. primeralph
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    Imma just say, equate the two y's. Find an x. Then plug into any one of the equations.

    • 11 months ago
  54. adl_thoo
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    its fine.. & okay, ive gotten so confused. idk what to do :(

    • 11 months ago
  55. primeralph
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    @adl_thoo cheeel

    • 11 months ago
  56. smokeydabear
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    Okay I just confirmed that it is B

    • 11 months ago
  57. Luigi0210
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    And no you were right the answer is A or whatever the points are

    • 11 months ago
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  58. smokeydabear
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    The graph threw me off, I just went brute force and plugged everything in, and only (16, 316) worked.

    • 11 months ago
  59. adl_thoo
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    so its B ?

    • 11 months ago
  60. smokeydabear
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    But aren't they equal at (16, 316)? Luigi, can you plug in the points into the equations to check?

    • 11 months ago
  61. Luigi0210
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    As it turns out both work :/

    • 11 months ago
  62. Luigi0210
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    So adl was right after all

    • 11 months ago
  63. smokeydabear
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    Oh look, my calculator was messing with me. Yes both work.

    • 11 months ago
  64. smokeydabear
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    My calculator never did like order of operations -.-

    • 11 months ago
  65. primeralph
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    |dw:1368580026141:dw|

    • 11 months ago
  66. primeralph
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    yo, was I too late?

    • 11 months ago
  67. Luigi0210
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    Naw :P

    • 11 months ago
  68. adl_thoo
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    noo . im still figuring this out.

    • 11 months ago
  69. smokeydabear
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    We were struggling for a long time and eventually got it, but your input helps reassure us, or me at least ^^

    • 11 months ago
  70. primeralph
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    plug in both 5 and 16 separately into eq A. That gives the number of people

    • 11 months ago
  71. adl_thoo
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    Sooo , wasit A B or C ?

    • 11 months ago
  72. Luigi0210
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    My stupidity has made this a bit harder than it needed to be

    • 11 months ago
  73. Luigi0210
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    and C

    • 11 months ago
  74. smokeydabear
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    It is C, because both work.

    • 11 months ago
  75. smokeydabear
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    That was extremely stressful...

    • 11 months ago
  76. adl_thoo
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    lol, itss, yay !! :D thanks guys.

    • 11 months ago
  77. primeralph
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    I don't know what the options are. It's really not stressful at all

    • 11 months ago
  78. adl_thoo
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    veryyyy !

    • 11 months ago
  79. primeralph
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    errr.............I knew what to do.............

    • 11 months ago
  80. adl_thoo
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    shoot, i didnt.

    • 11 months ago
  81. Luigi0210
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    It was just because I graphed the wrong equations :l

    • 11 months ago
  82. smokeydabear
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    It was only confusing because of Luigi's graph! >:0 But it's okay Luigi, I still wuv you <3

    • 11 months ago
  83. primeralph
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    so what did you get?

    • 11 months ago
  84. Luigi0210
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    Next time don't listen to me :P

    • 11 months ago
  85. adl_thoo
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    its okay guys :) we got it as The attendance was the same on days 5 and 16. The attendance at both plays on those days was 151 and 316 respectively.

    • 11 months ago
  86. primeralph
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    yeah

    • 11 months ago
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