问题
填空题
lg25+
|
答案
由题意得lg25+
lg8+lg5•lg20+lg222 3
=2lg5+2lg2+lg5(2lg2+lg5)+(lg2)2
=2(lg5+lg2)+2lg5lg2+(lg5)2+(lg2)2
=2+2lg5lg2+(lg5)2+(lg2)2
=2+(lg2+lg5)2
=2+1=3
所以lg25+
lg8+lg5•lg20+lg22=32 3
lg25+
|
由题意得lg25+
lg8+lg5•lg20+lg222 3
=2lg5+2lg2+lg5(2lg2+lg5)+(lg2)2
=2(lg5+lg2)+2lg5lg2+(lg5)2+(lg2)2
=2+2lg5lg2+(lg5)2+(lg2)2
=2+(lg2+lg5)2
=2+1=3
所以lg25+
lg8+lg5•lg20+lg22=32 3