25的x次方=2000
∴x=log25 2000
1/x=log2000 25
同理
1/y=log2000 80
∴1/x+1/y=log2000 25+log2000 80=1
(3x+3y)/2xy
=3/2(1/x+1/y)
=3/2log是？我，初二！换一种思路25的x次方=20002000^(1/x)=(25^x)^(1/x)=25 2000^(1/y)=80∴2000^(1/x)×2000^(1/y)=25×802000^(1/x+1/y)=2000∴1/x+1/y=1 (3x+3y)/2xy=3/2(1/x+1/y)=3/2