lg2^x+lg8^y=lg4lg(2^x*8^y)=lg42^x*8^y=42^x*2^(3y)=42^(x+3y)=4=2^2x+3y=21/x+1/(3y)=(x+3y)/(3xy)=2/(3xy)2=x+3y≥2√(3xy)当x=3y时取等号所以3xy≤1所以1/x+1/(3y)=)=2/(3xy)≥21/x+1/(3y)的最小值是2...