:(lg5)的2方+lg2乘lg50xiexie

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:(lg5)的2方+lg2乘lg50xiexie:(lg5)的2方+lg2乘lg50xiexie:(lg5)的2方+lg2乘lg50xiexie(lg5)^2+lg2*lg50=lg5*lg5+lg2

:(lg5)的2方+lg2乘lg50xiexie
:(lg5)的2方+lg2乘lg50
xiexie

:(lg5)的2方+lg2乘lg50xiexie
(lg5)^2+lg2*lg50
=lg5*lg5+lg2*(lg5+lg10)
=lg5*lg5+lg2*(lg5+1)
=lg5*lg5+lg2*lg5+lg2
=lg5(lg5+lg2)+lg2 [这一步很重要]
=lg5*lg(5*2)+lg2
=lg5+lg2
=lg(5*2)
=lg10
=1
楼上把lg2打成了l2

(lg5)^2+lg2*lg50
=lg5*lg5+l2*(lg5+lg10)
=lg5*lg5+l2*(lg5+1)
=lg5*lg5+l2*lg5+lg2
=lg5(lg5+l2)+lg2
=lg5*lg(5*2)+lg2
=lg5+lg2
=lg(5*2)
=lg10=1

(lg5)^2+lg2*(1+lg5)=lg2+lg5*(lg5+lg2)=lg5+lg2=1