对数的简单求值：lg²5+1g21g5+1g20如题,答案别太简略就行了,新手分少,

对数的简单求值：lg²5+1g21g5+1g20如题,答案别太简略就行了,新手分少,
对数的简单求值：lg²5+1g21g5+1g20
如题,答案别太简略就行了,
新手分少,

对数的简单求值：lg²5+1g21g5+1g20如题,答案别太简略就行了,新手分少,
lg²5+1g21g5+1g20
=lg5(lg5+1g2)+1g2+lg10
=lg5+lg2+1
=2

lg5lg5+lg2lg5+lg20
=lg5（lg5+lg2）+lg20
=lg5lg（5*2）+lg20
=lg5lg10+lg20
=lg5+lg20
=lg（5*20）
=lg100
=2