TITLE: Two inequalities involving the rearrangement inequality
QUESTION [6 upvotes]: Well, there are two more inequalities I'm struggling to prove using the Rearrangement Inequality (for $a,b,c>0$):
$$ 
a^4b^2+a^4c^2+b^4a^2+b^4c^2+c^4a^2+c^4b^2\ge 6a^2b^2c^2
$$
and 
$$a^2b+ab^2+b^2c+bc^2+ac^2+a^2c\ge 6abc
$$
They seems somewhat similar, so I hope there'a an exploitable link between them. They fall easily under Muirhead, yet I cannot figure out how to prove them using the Rearrangement Inequality. 
Any hints greatly appreciated.

REPLY [2 votes]: \begin{eqnarray*}
a(b-c)^2+b(c-a)^2+c(a-b)^2 \geq 0
\end{eqnarray*}
and the second inequality follows. Now substitute $a^2$ for $a$ etc and the first inequality follows.