take "ln's" of both sides:
ln (5^x) = ln (4^[x+1])
then
x * ln 5 = [x+1] * ln 4
xln5 = xln4 + ln4
x = (ln 4) / (ln 5 - ln 4)
2006-06-19 17:08:16
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answer #1
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answered by Anonymous
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5^x = 4^(x + 1)
Get the (x + 1)th root of both sides:
5^[x/(x + 1)] = 4
Convert into logarithmic form:
log_5 (4) = x/(x + 1)
Multiply by x + 1
(x + 1) (log_5 (4)) = x
distribute
log_5 (4) x + log_5 (4) = x
transpose x and log_5 (4)
log_5 (4) x - x = - log_5 (4)
Factor out x
x[log_5 (4) - 1] = - log_5 (4)
Multiply by -1
x[1 - log_5 (4)] = log_5 (4)
Divide
x = log_5 (4)/[1 - log_5 (4)]
Hope this helps^_^
^_^
2006-06-20 06:27:27
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answer #2
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answered by kevin! 5
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log both sides:
log(5^x) = log (4^(x+1))
Use the exponent property:
x(log 5) = (x+1)(log 4)
Distribute:
x(log 5) = x(log 4) + log 4
Move the x's to one side:
x(log 5) - x(log 4) = log 4
Factor out x:
x(log 5 - log 4) = log 4
Isolate the x:
x = (log 4) / (log 5 - log 4)
2006-06-20 00:08:17
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answer #3
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answered by fairyqueen 5
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5^x = 4^(x + 1)
xln5 = (x + 1)ln4
xln5 = xln4 + ln4
xln5 - xln4 = ln4
x(ln5 - ln4) = ln4
x = (ln4)/(ln5 - ln4)
x = about 6.212567
ANS : x = about 6.21
2006-06-20 00:17:30
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answer #4
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answered by Sherman81 6
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Yes -- it is logarithmic.
so:
LN(5^x) = LN(4^(X+1))
x*LN(5) = (x+1)*LN(4)
x*LN(5) = x*LN(4) + LN(4)
x*(LN(5)-LN(4)) = LN(4)
X*LN(5/4) = LN(4)
X = LN(4)/LN(5/4)
2006-06-20 00:12:15
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answer #5
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answered by Ranto 7
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5^x=4^(x+1)
5^x=4^x*4
5^x/4^x=4
(5/4)^x=4
xln(5/4)=ln4
x=ln4/ln(5/4)=0.602/0.096
x=6.27
2006-06-20 01:08:52
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answer #6
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answered by roniexz 1
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ya can say
x comes to be 6.21256
2006-06-20 00:07:09
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answer #7
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answered by Great Advisor 2
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i am not sure!!
y=5^x=4^(x+1)
so logy(base5)=logy(base4)-1
logy(base4)-logy(base5)=1
1/log4(basey)-1/log5(basey)=1
so {log5(basey)-log4(basey)}
/{log4(basey)*log5(basey)}=1
log(5/4)base(y)/
{log4(basey)*log5(basey)}=1
log (5/4)base4=log5(baesy)
(1/8)log5(base2)=log5(baesy)
8=logy(base2)
so y=2^8 and X=8*log2(base5)
2006-06-20 02:56:06
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answer #8
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answered by zilla_mafia 2
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