化简.1/3(lg16+log5 25-lg1/5)-lg0.2 注；log5 25是以5为底25的对数.

=1/3(lg80+2)-lg1/5
=1/3(lg80+lg100)-lg1/5
=1/3lg8000-lg1/5
=lg20-lg1/5
=lg100=2

原式=1/3(lg16+log5 25-lg1/5)-lg0.2
=1/3(4lg2+2+lg5)+lg5
=4/3lg2+4/3lg5+2/3
=4/3lg10+2/3
=4/3+2/3
=2

原式
=1/3(lg16+2+lg5)+lg5
=1/3(lg80+2)+lg5
=1/3(lg8+lg10+2)+lg5
=1/3(3lg2+3)+lg5
=lg2+lg5+1
=lg(2*5)+1
=2

希望我的回答对你有帮助,采纳吧O(∩_∩)O!