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Math Help - need help with two problems

  1. #1
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    need help with two problems

    12x - 2y -4 x equals 8 and y equals -6 Is it 80 or 104?

    is (2/3) -4 (that's a negative to the fourth power equal to -3/2
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  2. #2
    Forum Admin topsquark's Avatar
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    Quote Originally Posted by duckpluckie View Post
    12x - 2y -4 x equals 8 and y equals -6 Is it 80 or 104?
    12*8 - 2*(-6) - 4 = 96 - (-12) - 4 = 96 + 12 - 4 = 104

    -Dan
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  3. #3
    Forum Admin topsquark's Avatar
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    Quote Originally Posted by duckpluckie View Post
    is (2/3) -4 (that's a negative to the fourth power equal to -3/2
    Is it (2/3)^{-4} ie (2/3) to the "-4" power?

    The "-" on the 4 in the exponent means "flip the fraction over" so

    (2/3)^{-4} = (3/2)^4 = (3^4)/(2^4) = 81/16

    -Dan
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  4. #4
    dan
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    Quote Originally Posted by duckpluckie View Post
    12x - 2y -4 x equals 8 and y equals -6 Is it 80 or 104?

    is (2/3) -4 (that's a negative to the fourth power equal to -3/2

    i don't understand your problem... are you saying y=-6
    12x -[(2)*(-6)]-4x = 8
    12 x -4x = 20
    8x=20
    x=2.5

    or are you saying x=8 and y=-6
    (12*8) - (2*-6)-(4*8)
    = 96 +12 - 32
    =76 ??????

    dan
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  5. #5
    dan
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    Quote Originally Posted by topsquark View Post
    12*8 - 2*(-6) - 4 = 96 - (-12) - 4 = 96 + 12 - 4 = 104

    -Dan

    you did much better at understanding that then me.....



    ~dan
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  6. #6
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    frustrated and flummoxed

    I don't have the correct math symbols - what I am trying to do is find out if
    -3/2 is equivalent to (2/3) with a - tiny 4 - (a negative 4th power) Sorry I can't do better - I am a behavioral psych who play with primates and counts on her fingers and toes
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  7. #7
    Forum Admin topsquark's Avatar
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    Quote Originally Posted by duckpluckie View Post
    I don't have the correct math symbols - what I am trying to do is find out if
    -3/2 is equivalent to (2/3) with a - tiny 4 - (a negative 4th power) Sorry I can't do better - I am a behavioral psych who play with primates and counts on her fingers and toes
    First, please post responses as a reply in the original thread. It makes for easier reading. Hopefully one of the mods will move it there.

    Apparently my guess in the other thread is correct. So as I showed there:
    (2/3)^{-4} = 81/16 is NOT equal to -3/2.

    Don't worry about not knowing the symbols. We'll figure it out sooner or later.

    -Dan
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  8. #8
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    Quote Originally Posted by topsquark View Post
    First, please post responses as a reply in the original thread. It makes for easier reading. Hopefully one of the mods will move it there.
    tada..

    RonL
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