Ask your own question, for FREE!
Algebra 7 Online
OpenStudy (anonymous):

2^3x-4=5 round to the nearest ten thousandth

OpenStudy (solomonzelman):

the x is not part of the exponent correct?

OpenStudy (anonymous):

it is

OpenStudy (solomonzelman):

\[\huge\color{blue}{ 2^{3x}-4=5 } \]

OpenStudy (anonymous):

is the 3x the exponent?

OpenStudy (solomonzelman):

Add 4 to both sides, and hit both sides with a log.

OpenStudy (anonymous):

ok

OpenStudy (solomonzelman):

\[\huge\color{blue}{ 2^{3x}-~4~=~5 } \]\[\huge\color{blue}{ 2^{3x}-~4~\huge\color{red}{ +~4 } ~=~5 \huge\color{red}{ ~+~4 } } \]\[\huge\color{blue}{ 2^{3x} ~=~9 }\]\[\huge\color{blue}{ Log(2^{3x}) ~=~Log(9) }\]

OpenStudy (solomonzelman):

\[\huge\color{blue}{ 3x~Log(2) ~=~Log(9) }\] \[\huge\color{blue}{ 3x~Log(2) \color{red} { \div Log (2) }~=~Log(9) }\color{red} { \div Log (2) }\] \[\huge\color{blue}{ 3x=~Log(9) }\color{blue} { \div Log (2) }\] \[\huge\color{blue}{ 3x=~Log_2(9) }\] \[\huge\color{blue}{ x=~Log_2(9) \div 3}\] \[\huge\color{blue}{ x=~Log_2(9) \div Log_2(6)}\] \[\huge\color{blue}{ x=~Log_6(9)}\]

OpenStudy (solomonzelman):

Actually, I am not sure about the very last step.

OpenStudy (anonymous):

ok

OpenStudy (solomonzelman):

Yeah, the last step is correct, I just verified it.

OpenStudy (solomonzelman):

http://www.1728.org/logrithm.htm

OpenStudy (solomonzelman):

calculate the log when you need, where it says "logarithm of" on 1 space to the right put the number the log of which you are taking where it says "number base" put in the next space to the right, the base of the log. (if not specified which base, put 10)

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!