Answer
$2x^{2}(y-14z)(y-z)$
Work Step by Step
First, there is a GCF (of all terms), GCF=$2x^{2}$
$...=2x^{2}(y^{2}-15yz+14z^{2})$
Searching for two factors of $14z^{2}$ such that their sum is $-15z...$
we find $-14z$ and $-z.$
= $2x^{2}(y-14z)(y-z)$
All are prime, factorization is complete.