Question

Напишите решение, плиз!
log8 (12)- log8 (15) + log8 (20)=?
log9 (15)+log9 (18) - log9 (10)=?

Answer 1

$log_{8}12 - log_{8}15 + log_{8}20 = log_{8} (frac{12}{15}*20)= log_{8}16 =$
= $log_{2 ^{3}} 2^{4} = frac{4}{3}= 1 frac{1}{3}$

2) $log_{9}( frac{15*18}{10}) = log_{9}27= log _{3 ^{2} }3 ^{3}= frac{3}{2}= 1,5$