[h=1]How would i go about solving things such as 4^(3x+2)=16*7^(x+5)? Initially I took the natural log of both sides, and multiplied the 16 through but thats throwing me off, nor do I think my answer was correct. Please explain, and thank you! [/h]
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Exponential equations
- Thread starter zschnopz
- Start date
\(\displaystyle 4^{3 x+2}=16 *\ 7^{x+5}\)
now take logs on both sides
\(\displaystyle (3 x+2) \ln (4)=(x+5) \ln (7)+\ln (16)\)
and solve for x
the answer is
\(\displaystyle x = \frac{-2 \ln (4)+5 \ln (7)+\ln (16)}{3 \ln (4)-\ln (7)}\)
No, that's not the answer. \(\displaystyle \ \)It's not simplified. \(\displaystyle \ \)For instance,
the portion of the numerator
\(\displaystyle \ -2 \ln(4) + \ln(16) =\)
\(\displaystyle - \ln(4^2) + \ln(16) = \)
\(\displaystyle -\ln(16) + \ln(16) = 0.\)
Last edited:
D
Deleted member 4993
Guest
No, that's not the answer. \(\displaystyle \ \)It's not simplified. \(\displaystyle \ \)For instance,
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Sometimes - it is good to leave some part of the answer to be completed by OP.
However, in that case we should end by saying "now continue....." (my opinion)