(log5根号2*log49^81)/(log25^(1/3)*log7^立方根4)
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/01 22:53:12
![(log5根号2*log49^81)/(log25^(1/3)*log7^立方根4)](/uploads/image/z/1663447-31-7.jpg?t=%28log5%E6%A0%B9%E5%8F%B72%2Alog49%5E81%29%2F%28log25%5E%281%2F3%29%2Alog7%5E%E7%AB%8B%E6%96%B9%E6%A0%B94%29)
(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.