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    3^x=11^2x+4

    please help i know its something to do with ln
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    (Original post by cashmoneyorg)
    3^x=11^2x+4

    please help i know its something to do with ln

    take logs of both sides?
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    it could be ln it could be log base anything. a log rule would be useful here, log-base-a B^c= c log-base-a B
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    Do you know that a^2x can be written as (a^x)^2?
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    Is the RHS 11^(2x+4) or 11^(2x) + 4?
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    11^(2x+4)
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    (Original post by Adam92)
    Is the RHS 11^(2x+4) or 11^(2x) + 4?
    11^(2x+4)
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    well as was previously said you take the logs on both sides
    x log (3)= (2x +4) log(11)
    then you distribute
    x log (3)=2xlog(11) +4 log(11)
    then move the x to the other side, factor the x out and do the remaining algebra
    x(log(3)-2log(11))=4 log(11)

    x=4log(11)/(log(3)-2log(11))

    that gives you the correct result
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    bump*
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    (Original post by cashmoneyorg)
    bump*
    The previous post gave you the solution!
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    (Original post by RichE)
    The previous post gave you the solution!
    sorry didn't see it when i bumped
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    (Original post by RichE)
    The previous post gave you the solution!
    sorry didn't see it when i bumped
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    (Original post by mel3)
    well as was previously said you take the logs on both sides
    x log (3)= (2x +4) log(11)
    then you distribute
    x log (3)=2xlog(11) +4 log(11)
    then move the x to the other side, factor the x out and do the remaining algebra
    x(log(3)-2log(11))=4 log(11)

    x=4log(11)/(log(3)-2log(11))

    that gives you the correct result
    thanks repped
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    (Original post by cashmoneyorg)
    3^x=11^2x+4

    please help i know its something to do with ln
    i worked out x as being equal to 4log(11)/log(3)-2log(11) did it in 2 min!
 
 
 
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