x^5=729
5log(x)=log(729)
log(x)=Log(729)/5=0.5725
x=10^.5725
x=3.7368, because 3.7368^5=729(rounded)
You only need to use logs when you are looking for an index. Here is another way :)
\(x^5=729\\ (x^5)^{1/5}=729^{1/5}\\ x\approx 3.7371928\)
