1) = log_{15} (5*3) = log_{15}15 = 1;
3) = log_{5}( \frac{50}{2} ) = log_{5}25 = 2;
4) = [tex] log_{3} ( \frac{ \frac{1}{6} }{ \frac{81}{2} } ) = log_{3} \frac{1}{243} =
log_{3} 3^{- 5} =- 5;
2) = log_{0,1} (5*2) = log_{0,1} 10 = log_{0,1} 10^{-1} = -1;
6) = [tex] log_{13} ( 13^{ \frac{2}{5} } ) = \frac{2}{5};
5) = [tex] log_ 2 2^{3*7} = 2^{21} =21;