Brook L.

asked • 02/05/18

7=(1/3)^2x-1 What does x equal

Solve for x

Inactive Tutor

Student,
 
Do you mean
 
7 = (1/3)2x - 1
 
or
 
7 = (1/3)2x-1
 
?
Report

02/05/18

Brook L.

7 = (1/3)2x-1 Sorry that I didn't state it clearly.
Report

02/05/18

1 Expert Answer

By:

Inactive Tutor answered • 02/05/18

Tutor
New to Wyzant

See tutors like this
See tutors like this
Not sure if you have worked with logarithms yet but logs undo exponents. Logs and exponents are inverses of each other.
Take the log base 10 of both sides of the equation.....log7 = (2x-1)log(1/3), then simplify.
2x-1 = log7/log(1/3). The log of a number is just a value. Try log7 on your calculator to see what value you get.
or x = [log7/log(1/3) + 1]/2      x = -0.386
 
Another approach using a change of bases..... log1/37 = 2x-1, x = -0.386
Upvote • 0 Downvote
More
Report

Inactive Tutor

Karyn, isn't it best to get the clarification requested by Arturo before working this problem?
 
Brook, here are some parentheses which you can use to clarify the problem:  ((  ))
Report

02/05/18

Brook L.

7=(1/3)(2x-1)
Report

02/05/18

Brook L.

Thank you!
Report

02/05/18

Still looking for help? Get the right answer, fast.

Ask a question for free

Get a free answer to a quick problem.
Most questions answered within 4 hours.

OR

Find an Online Tutor Now

Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.