Consider $2xy+xz-2y^{2}-yz$. Do the grouping $2xy+xz-2y^{2}-yz=\left(2xy+xz\right)+\left(-2y^{2}-yz\right)$, and factor out $x$ in the first and $-y$ in the second group.
$$x\left(2y+z\right)-y\left(2y+z\right)$$
Factor out common term $2y+z$ by using distributive property.
