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Math Help - Help with logarithms!

  1. #1
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    Exclamation Help with logarithms!

    Please help me figure out how to solve the following:

    1) 4^(x+2) = 16^(2x-2)

    2) log SUB 3(5x+1) = 4

    3) 4^(4x+1) = 8^(3x)

    Thanks in advance!
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  2. #2
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    Quote Originally Posted by kcwillia377 View Post
    Please help me figure out how to solve the following:

    1) 4^(x+2) = 16^(2x-2)

    note that 4^2 = 16

    2) log SUB 3(5x+1) = 4

    change to an exponential equation ... 3^4 = 5x+1

    3) 4^(4x+1) = 8^(3x)

    note that 8 = 2^3 and 4 = 2^2
    .
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  3. #3
    Senior Member Pinkk's Avatar
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    1) log(4^{x+2})=log(16^{2x-2})

    (x+2)log(2^{2})=(2x-2)log(2^{4})

    (2x+4)log(2)=(8x-8)log(2)

    2x+4=8x-8

    12=6x

    x=2

    2) 3^{4}=5x+1

    80=5x

    x=16

    3) log(4^{4x+1})=log(8^{3x})

    (4x+1)log(2^{2})=(3x)log(2^{3})

    (8x+2)log(2)=(9x)log(2)

    8x+2=9x

    x=2
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