logalepe 2 ve, ta dc: ((a+b+c)/3) ln(abc)\geq ln(a^a*b^b*c^c)
\Leftrightarrow (a+b+c)[lna+ lnb+ lnc]\geq3*[alna+ blnb+ clnc]
\Leftrightarrowalnb+ alnc+ blna+ blnc+ clna+ clnb\geq2*(alna+ blnb+ clnc)
\Leftrightarrow(a-b)(lna-lnb)+ (b-c)(lnb-lnc)+ (c-a)(lnc-lna)\geq0
gia su a>=b>=c>0
a\geqb\Rightarrowlna\geqlnb \Rightarrow(a-b)(lna-lnb)\geq0
Tuong tu \Rightarrowdpcm
pan chep sai de pai rui phai la
cho a;b;c > 0 cmr (abc)^((a+b+c)/3)\geqa^a*b^b*c^c
nhu vay moi dung


