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,
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![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,](/uploads/image/z/3177691-43-1.jpg?t=%E5%AF%B9%E6%95%B0%E7%9A%84%E7%AE%80%E5%8D%95%E6%B1%82%E5%80%BC%EF%BC%9Alg%26%23178%3B5%2B1g21g5%2B1g20%E5%A6%82%E9%A2%98%2C%E7%AD%94%E6%A1%88%E5%88%AB%E5%A4%AA%E7%AE%80%E7%95%A5%E5%B0%B1%E8%A1%8C%E4%BA%86%2C%E6%96%B0%E6%89%8B%E5%88%86%E5%B0%91%2C)
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