Mathematics
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OpenStudy (anonymous):
How do i do this?????
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OpenStudy (anonymous):
OpenStudy (amistre64):
by remembering what the properties of exponents and logs are :)
OpenStudy (amistre64):
\[b^{n+m}=b^n*b^m\]
OpenStudy (anonymous):
i know that 4^-3 x 4^2log2(7)
OpenStudy (amistre64):
good so far
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OpenStudy (anonymous):
:]
OpenStudy (anonymous):
now is that 4^-3 x 2log2(7)=4?
OpenStudy (amistre64):
rewrite 2log2(7) as log2(49)
OpenStudy (anonymous):
okay
OpenStudy (amistre64):
if you introduce an = sign; you have to put an arbitrary variable over the to equate to
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OpenStudy (anonymous):
okay but is it okay to write like that?
OpenStudy (amistre64):
\[4^{log_2(49)}=4k\]is better
OpenStudy (anonymous):
okay \[\log _{4}81\] do u know how to write this function in the calculator?
OpenStudy (amistre64):
lost a ^3
OpenStudy (anonymous):
\[4^{-3}\times2\log _{2}49\]
0.015625x3.38
0.0528 u mean like this?
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OpenStudy (amistre64):
\[4^{-3}4^{log_2{49}}=k\]
\[4^{log_2{49}}=4^3k\]
\[log_4\{4^{log_2{49}}=4^3k\}\]
\[log_2(49)=3+log_4(k)\]
\[\frac{ln(49)}{ln(2)}=3+\frac{ln(k)}{ln(4)}\]
OpenStudy (anonymous):
k can be any variable like x?
OpenStudy (amistre64):
\[\frac{ln(4)ln(49)}{ln(2)}-3ln(4)=ln(k)\]
hmmm, we can e both sides but that doesnt seem like a simplification does it
OpenStudy (amistre64):
yes, its just a filler that you try to solve for
OpenStudy (amistre64):
i use k for some constant
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OpenStudy (anonymous):
okay thanks alot :]
OpenStudy (amistre64):
play around with it using the basic rules you know for exponents and logs and you should do fine
OpenStudy (amistre64):
then use wolfram for a dbl chk ;)
OpenStudy (anonymous):
3.621117=ln k