log_{49}7=x
49^x=7
7^{2x}=7^1
2x=1 |:2
x=\frac{1}{2}
log_{17}1=log_{17}17^0=0
log100000=log_{10}100000=log_{10}10^5=5
b)
log_{0,2}625=x
(\frac{1}{5})^x=5^4
(\frac{1}{5})^x=(\frac{1}{5})^{-4}
x=-4
log_{\sqrt3}27=x
(\sqrt3)^x=27
(\sqrt3)^x=3^3
(\sqrt3)^x=((\sqrt3)^2)^3
(\sqrt3)^x=(\sqrt3)^6
x=6
log_{16}2=x
16^x=2
2^{4x}=2^1
4x=1 |:4
x=\frac{1}{4}