How do you solve for x?: 2log_3(x) = 3 log_3(4)2log3(x)=3log3(4)

1 Answer
Oct 22, 2015

I found x=8x=8

Explanation:

We can use a rule of the log to write:
log_3(x^color(red)(2))=log_3(4^color(red)(3))log3(x2)=log3(43)

then take 33 to the power of the right and left side to cancel the logs:
color(blue)(3)^(log_3(x^color(red)(2)))=color(blue)(3)^(log_3(4^color(red)(3)))3log3(x2)=3log3(43)
cancel(color(blue)(3))^(cancel(log_3)(x^color(red)(2)))=cancel(color(blue)(3))^(cancel(log_3)(4^color(red)(3)))
and get:
x^2=4^3=64
x=+-sqrt(64)=+-8
we can use only the positive one x=8.