ChapterChapter 7 logs solve for x

Assuming the problem is x = log 15^{2/3}:

The argument of a log raised to a power is the same as the power times the log function, or:

log 15^{2/3} = (2/3) log 15

To determine log 15, I'll refer to my calculator and I get 1.17609. Mutliply by 2/3 to get 0.78406

So 0.78406 = log 15^{2/3}