lnx，x>e

If a, b and c are not equal to each other,

And f(a)=f(b)=f(c),

Suppose a < b < c,

According to the known conditions:

0 0； There is always f (x) < 0 in (2, +∞).

And because f(x) is a odd function defined on R,

So there is always f (x) > 0 in (-∞, -2); There is always f (x) < 0 in (-2,0).

And the solution set of inequality X2F (x) > 0, that is, the solution set of inequality F (x) > 0.

So the answer is: (-∞,-2) ∩ (0,2).

I don't understand three or five questions, sorry.