log函数的简单计算

问题描述:

log函数的简单计算
(lg2)^2+lg5*lg20-1=_________  求过程!

(lg2)^2+lg5*lg20-1
=(lg2)^2+lg5*(lg2+lg10)-1
=(lg2)^2+lg5*lg2+lg5-1
=lg2*(lg2+lg5)+lg5-1
=lg2*lg10+lg5-1
=lg2+lg5-1
=lg10-1
=0