化简lg25+2/3lg8+lg5×lg20+(lg^2)2

分类: 作业答案 • 2021-12-19 16:55:52

问题描述：

答

lg25+2/3lg8+lg5×lg20+(lg^2)2
=2lg5+2lg2+lg5x(lg5+lg4)+(lg2)²
=2(lg5+lg2)+(lg5)²+2lg5*lg2+(lg2)²
=2+（lg2+lg5）²
=2+1²
=3

答

lg25+2/3lg8+lg5×lg20+(lg^2)2
=lg25+lg4+lg5×lg20+lg²2
=2+lg5×(1+lg2)+lg²2
=2+lg5+lg2×(lg5+lg2）
=2+lg5+lg2
=2+lg10
=2+1
=3