lg5×lg20＋（lg2)的平方得多少?

来源：学生作业学帮网编辑：学帮网时间：2024/05/30 12:18:59

lG(5)*LG(20)+(LG(2))^2
=LG(5)*(LG(4)+LG(5))+(LG(2))^2
=(lG(5))^2+2LG(5)*LG(2)+(LG(2))^2
=(LG(5)+LG(2))^2
=(LG(10))^2=1

=(1-lg2)(1+lg2)+lg²2
=1-lg²2+lg²2
=1