帮我算道题:计算2lg5+2/3lg8+lg5lg20+(lg2)

问题描述:

帮我算道题:计算2lg5+2/3lg8+lg5lg20+(lg2)

后面的(lg2)少了个平方
2lg5 + 2/3lg8 +l g5lg20 + lg²2
=2lg5 + 2lg2 + lg5lg20 + lg²2
=2(lg5+lg2) + lg5(lg5+2lg2) + lg²2
=2 + lg²5 + 2lg5lg2 + lg²2
=2+(lg5+lg2)²
=2+1
=3