lg25+2/3lg8+lg5*lg20+(lg2)^2=?
问题描述:
lg25+2/3lg8+lg5*lg20+(lg2)^2=?
答
原式=2lg5+2lg2 +lg5(lg5+2lg2)+(lg2)^2
=2(lg5+lg2)+(lg2)^2+2lg2lg5+(lg5)^2
=2lg10+[lg2+lg5]^2
=2+1^2
=2+1
=3