lg^2 5+lg2*lg5+lg20=计算

lg^2 5+lg2*lg5+lg20=计算
lg^2 5+lg2*lg5+lg20=
计算

lg^2 5+lg2*lg5+lg20=计算
lg5(lg5+lg2)+lg10 +lg2
=lg5(lg10)+1+lg2
=lg5+lg2+1
=lg10+1
=1+1
=2

(lg5)^2+lg2*lg5+lg20
=lg5(lg5+lg2)+lg20
=lg5+lg20
=lg100
=2

=2
过程
=lg5*（lg5+lg2）+lg10+lg2
=lg5+lg2+lg10
=2