log27^4*log8^9+2log4^9-4 - 知识问答

log27^4*log8^9+2log4^9-4 要崩溃了- -表示不认真听课的下场啊..

3个回答

应该是log27^4*(log8^9+2log4^9)-4
=lg4/lg27*(lg9/lg8+2lg9/lg4)-4
=2lg2/3lg3*(2lg3/3lg2+2lg3/lg2)-4
=2lg2/3lg3*(8/3*lg3/lg2)-4
=16/9-4
=-20/9

相关问题