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Math Help - How would i do this work out?

  1. #1
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    How would i do this work out?

    I need the break down on how to get the answer please.

    8 21/22+3/4-5/12=?


    The eight is a mix number with twenty one and twenty two
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  2. #2
    No one in Particular VonNemo19's Avatar
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    Quote Originally Posted by Math Noob View Post
    I need the break down on how to get the answer please.

    8 21/22+3/4-5/12=?


    The eight is a mix number with twenty one and twenty two
    Im not sure what the 8 is doing there, but let's pretend that it isnt because the idea is the same.

    You need to find a common denominator here...

    Do you know how?
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  3. #3
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    the eight is the whole number of 8 21/22

    you have to multiply 22 by 8 and then add the 21 correct?

    i got that part figured out now what's next? find the common denominator of each fraction?
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  4. #4
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    Quote Originally Posted by Math Noob View Post
    I need the break down on how to get the answer please.

    8 21/22+3/4-5/12=?


    The eight is a mix number with twenty one and twenty two
    8\frac{21}{22} + \frac{3}{4} - \frac{5}{12}

    Find the LCM of 22, 4 and 12 which is 132 also that 8 can also be written as \frac{8 \times 22}{22}
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  5. #5
    No one in Particular VonNemo19's Avatar
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    Quote Originally Posted by Math Noob View Post
    the eight is the whole number of 8 21/22

    you have to multiply 22 by 8 and then add the 21 correct?
    Correct! Sorry that I didn't notice that, by the way. So we will have...


    \frac{176}{22}


    So, now what should we do? The common denominator, right.
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  6. #6
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    how did you find the common denominator so fast?
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  7. #7
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    Quote Originally Posted by Math Noob View Post
    how did you find the common denominator so fast?
    Using prime factors.

    22 = 2 x 11
    12 = 2 x 2 x 3

    Multiply any unique prime factors: 2 x 2 x 3 from 12 and 11 from 22:

    2 \times 2 \times 3 \times 11 = 132
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  8. #8
    No one in Particular VonNemo19's Avatar
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    Quote Originally Posted by Math Noob View Post
    how did you find the common denominator so fast?
    I will stand down now.
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  9. #9
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    lol im still trying to figure it out
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  10. #10
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    the answer is 9 19/66
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  11. #11
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    e^(i*pi)'s Avatar
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    Quote Originally Posted by Math Noob View Post
    lol im still trying to figure it out
    \frac{197}{22} + \frac{3}{4} - \frac{5}{12}

    As this does not ask for the LCM you don't need to use it - you can cross multiply if you wish

    I don't see why you don't number crunch it?
    Last edited by e^(i*pi); September 13th 2009 at 10:15 AM. Reason: oops wrong sign
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  12. #12
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    because i am a noob, and would love to know how to number crunch
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  13. #13
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    By using a calculator and putting in the numbers

    \frac{197}{22} + \frac{9}{12} - \frac{5}{12}

    LCM is 132

    <br />
(\frac{197}{22} \times \frac{6}{6}) + (\frac{9}{12} \times \frac{11}{11}) - (\frac{5}{12} \times \frac{11}{11})

    = \frac{1182}{132} + \frac{99}{132} - \frac{55}{132}

    = \frac{1182+99-55}{132}

    which should give the answer
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  14. #14
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    I have a ti-84 plus i just purchased, I'm trying to figure out how to use it.
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  15. #15
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    I edited my above post to include the answer
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