(log5根号2*log49^81)/(log25^(1/3)*log7^立方根4)

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(log5根号2*log49^81)/(log25^(1/3)*log7^立方根4)

(log5根号2*log49^81)/(log25^(1/3)*log7^立方根4)
(log5根号2*log49^81)/(log25^(1/3)*log7^立方根4)

(log5根号2*log49^81)/(log25^(1/3)*log7^立方根4)
用换底公式,
原式=[(1/2)(lg2*/lg5)*(4lg3)/(2lg7)]/{[lg(1/3)/(2lg5)]*[(2/3)lg2/lg7}
=(2lg2*lg3)/2lg5lg7)*[(-2lg3lg5/3)/(2lg5lg7)
=2lg2lg3lg5lg7/[(2lg5lg7/3)(-lg3lg2)]
=-3.