I'm trying to prove that $15n+7$ is $o(n\log n)$ (by first principles, i.e. no limits).
My idea is to solve for n to determine $n_0$ and then work backwards from there. But I can't seem to find a way.
$15n+7 < cn\log n$
$7 < n(c\log n-15)$
I got stuck here.