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求值lg2lg50+lg5lg20-log3(4)log2(3)lg2lg5

题目详情
求值lg2lg50+lg5lg20-log3(4)log2(3)lg2lg5
▼优质解答
答案和解析
lg2lg50 + lg5lg20 - log3(4)log2(3)lg2lg5
= lg2(lg100 - lg2) + (1 - lg2)(lg2 + lg10) - 2log3(2)log2(3)lg2lg5
= lg2(2 - lg2) + 1 -lg²2 -2lg2(1 - lg2)
= 2lg2 - lg²2 + 1 - lg²2 - 2lg2 + 2lg²2
= 1