stuck on math

Discussion in 'Single Subject Tests' started by JaimeMarie, Apr 13, 2008.

  1. JaimeMarie

    JaimeMarie Moderator

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    Apr 13, 2008

    I have the answer but I can't get to the answer for some reason. I think I must be doing something wrong.

    1) 9/y=3/4

    I did 1/9 * 9/y=3/4*1/9

    y=1/12 but the answer in the book says it should be 12.
     
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  3. Peachyness

    Peachyness Virtuoso

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    I think they just want what y would be. Because if it's 9/12, then it reduces to 3/4. Right???
     
  4. INteacher

    INteacher Aficionado

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    Apr 13, 2008

    you need to cross multiply

    9*4=y*3
    36=3y divide both sides by 3
    y=12

    not a math person but I am pretty sure this is the correct way to solve. I think this is set up like a ratio.
     
  5. Proud2BATeacher

    Proud2BATeacher Phenom

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    This is the way that I would do it
     
  6. Malcolm

    Malcolm Enthusiast

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    Apr 13, 2008

    9/y = 3/4

    1/9 * 9/y = 3/4 * 1/9

    1/y = 3/36 = 1/12

    You aren't done yet, you have 1/y not y.
    Take the reciprocal of both sides.

    y = 12
     
  7. JaimeMarie

    JaimeMarie Moderator

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    Thanks everyone!

    Slapping self on head thanks Malcolm
     
  8. JaimeMarie

    JaimeMarie Moderator

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    Well I got the rest of the questions in that section right! YIPPIE. I'm on section two of chapter five. I have two more weeks to study for this test that I really dont' feel like taking at all.
     
  9. TeacherGroupie

    TeacherGroupie Moderator

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    Think how good you'll feel when it's over and passed, Jaime...
     
  10. HMM

    HMM Cohort

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    Apr 13, 2008

    I would have taken the reciprocal first

    y/9=4/3

    then multiplied by 9 to both sides

    y=4/3*9=4*3=12
     
  11. Malcolm

    Malcolm Enthusiast

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    Apr 13, 2008

    Like I tell my students...

    There is more than one way to skin a cat.

    I like the idea of solving this problem as a proportion in this case. Solving the problem just comes down to multiplying two integers then dividing by an integer.
     
  12. TeacherGroupie

    TeacherGroupie Moderator

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    Apr 14, 2008

    Yup. There may be just one answer to a math problem, but there's rarely only one way to get there.
     

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