log_{0,2}\frac{1}{125}=
log_{0,2}\frac{1}{125}=x
(0,2)^x=\frac{1}{125}
0,2=\frac{1}{5}
(\frac{1}{5})^x=(\frac{1}{5})^3
x=3
Odp. log_{0,2}\frac{1}{125}=3