log(2)(25)×log(3)(1/16)×log(5)(1/9)=?
问题描述：
log(2)(25)×log(3)(1/16)×log(5)(1/9)=?
答
log(2)(25)×=lg25/lg2=2lg5/lg2 log(3)(1/16)=lg(1/16)/lg3=-4lg2/lg3 log(5)(1/9)=lg(1/9)/lg5=-2lg3/lg5 log(2)(25)×log(3)(1/16)×log(5)(1/9)=16