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Math Help

Discussion in 'Members' Lounge' started by reckedracing, Feb 17, 2010.

  1. reckedracing

    reckedracing TTIWWOP VIP

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    I forgot my old school math.
    Someone throw me a bone on this one.
    Would prefer to see it worked out.

    A+B=65
    A3+B2=179
     
  2. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    A + B = 65
    3*A + 2*B = 179

    A = 65-B

    substitute

    (65-B)*3 + 2*B = 179
    195 - 3*B + 2*B = 179
    195 - B = 179
    B = 16

    substitute again

    A = 65-16
    A = 49

    Easy
     
    1 person likes this.
  3. CRX-YEM

    CRX-YEM Super Moderator Moderator VIP

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    Could be done via matrices with cramers rule as well imho is a lot easier than the substitution method.
     
  4. reckedracing

    reckedracing TTIWWOP VIP

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    ahhhh
    i had the right path
    it was always the end that screwed me
    my second equation i solved A = 49 but then when i ran it back through i divided by 2 twice and ended up with
    147+B2=179
    B=8


    the first and third time i ended up with
    195-B3+B2=179
    195-B5=179
    -B5 = 16
    B = 3.2

    I thought I was making my beginning formulas wrong.
    Original question... don't ask...
    A farmer has three legged cows and chicken.
    There are 65 heads and 179 legs.
    How many cows does the farmer have.


    Is this the other method you were refering to CRXYEM
     
    Last edited: Feb 17, 2010
  5. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    I suppose- it's been too long though... plus I would normally just do it in my head via brute force in about 5-6 seconds- but that wouldn't give anything to go by in terms of "showing the work" in the thread. I really don't think it's anywhere near complex enough to use any specific method to solve it.
     
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