Cho ${{\log }_{2}}3=a$. Tính $P={{\log }_{8}}6$ theo $a$.

$P={{\log }_{8}}6={{\log }_{{{2}^{3}}}}\left( 2.3 \right)=\dfrac{1}{3}{{\log }_{2}}\left( 2.3 \right)=\dfrac{1}{3}\left( {{\log }_{2}}2+{{\log }_{2}}3 \right)=\dfrac{1}{3}\left( 1+{{\log }_{2}}3 \right)=\dfrac{1}{3}\left( 1+a \right)$