a=log18 9, b=log18 5所以,log36 45=(log18 45/log18 36)换底公式又log18 45=log18 (5*9)=（log18 5 ）+（log189)=a+blog18 36=log18(4*9)=(log18 9 )+【log18 (9-5)】=a+a/b所以,log36 45=(a+b)/(a+a/b)=(a...