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    I feel really stupid because i'm certain that this question is really easy i just can't do it right now. Would be really grateful if you could show/explain how to get the answer. It's the fact that ^x is on both sides that has me stumped.

    4^x+2=5^x
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    Assuming you mean 4^(x+2) = 5^x.....

    log (4^(x+2)) = log(5^x)

    (x+2)log4 = xlog5

    xlog4 + 2log4 = xlog5

    x(log5 - log4) = 2log4

    x = 2log4/(log5 - log4)
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    If you don't like x being on both sides, divide by 4^x:

    16 = (5/4)^x

    That kind of equation should be more familiar
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    thanks, i knew it was something simple, just too addled to get it
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    if its 2 + 4^x = 5^x, no idea. use an iteration to solve it. if on the other hand you meant 4(x+2) = 5x then its some simple log work.

    4(x+2) = 5x
    (x+2) ln4 = x ln5
    x(ln4 - ln5) = 2 ln4
    x = {ln16/ln0.8}
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    how did you get the third line from the 2nd one?
    (x+2) ln4 = x ln5
    xln4 + 2ln4 = xln5
    xln4 - xln5 = -2ln4
    x(ln4-ln5) = -2ln4

    Edit:
    forgot to continue!:
    x(ln4-ln5) = -2ln4
    -x(ln4-ln5) = 2ln4
    x(ln5-ln4) = 2ln4
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    haha... well i hate it when this "moment" comes while i'm in the exam!! :rolleyes:
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    hoho.. trust me: it did (to me)! A LOT!
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    haha... EVERY one...
    VERY stupid mistakes!
 
 
 
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Updated: April 11, 2006
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