Solving 2^(3x) - 16 = 11 for x.

[Math wiz ya rite 09]

Solve 2^(3x) - 16 = 11 for x. Leave your answer in the form "x = log_2(number or expression)".

My work:

. . .2^(3x) - 16 = 11

. . .2^(3x) = 27

Then I took the base-2 log of each side:

. . .3x = log_2(27)

Then would it be log base 2 of (27^(1/3))

which would be log base 2 of (3)

Is that the answer? Please let me know. Thank you!

 

[pka]

I get \(\displaystyle x = \frac{{\log _2 \left( {27} \right)}}{3}.\)

Can you tell us why?

 

[Math wiz ya rite 09]

I need to get my answer in the format of x = log base 2 of (# or expression)

Your answer is not in that format.

Please help. Thank you.

 

[tkhunny]

That looks like it.

Your life may have been a little simpler by observing:

\(\displaystyle 2^{3x}\;=\;(2^{x})^{3}\;=\;27\;=\;3^{3}\;\rightarrow\;2^{x}\;=\;3\)

But your way was fine.

 

[pka]

I need to get my answer in the format of x = log base 2 of (# or expression) Your answer is not in that format.

OH PLEASE DO FORGIVE ME!
I did no know how ‘mathematically challenged' you must be.
Of course, I am not sure why you think that you are in a position to demand a complete answer. But here it is: \(\displaystyle x = \log _2 \left( {\sqrt[3]{{27}}} \right) = \log _2 \left( 3 \right).\)

If you do not understand it, please do not respond!

 

[Math wiz ya rite 09]

im sorry, but sometimes i just like a straight forward answer.

 

[Denis]

im sorry, but sometimes i just like a straight forward answer.

Easier to give IF a straight forward question is asked :idea:

 

[stapel]

im sorry, but sometimes i just like a straight forward answer.

The tutors are here to help you learn, not to do your homework for you. Instead of complaining that the tutor "only" helped you, it might have been better if you'd tried to work from what he gave you.

Thank you for your consideration.

Eliz.