(lg5)^2+lg2·lg50=?求救...

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(lg5)^2+lg2·lg50=?求救...

(lg5)^2+lg2·lg50=?求救...
(lg5)^2+lg2·lg50=?
求救...

(lg5)^2+lg2·lg50=?求救...
lg²5+lg2•lg50
=lg²5+lg2•lg(5•10)
=lg²5+lg2•(lg5+lg10)
=lg²5+lg2•lg5+lg2
=lg5•(lg5+lg2)+lg2
=lg5•[lg(5•2)]+lg2
=lg5•lg10+lg2
=lg5+lg2
=lg(5•2)
=1

(lg5)^2+lg2·lg50 =(lg5)^2+lg2*lg(2*25)
=(lg5)^2+lg2*(lg2+lg25) =(lg5)^2+lg2*(lg2+2lg5)
=(lg5)^2+(lg2)^2+2lg5lg2 =(lg5+lg2)^2