I am stuck with solving this problem, does anybody has idea, how to solve it ?
Let $P$ and $Q$ be polyhedra in $\mathbb{R}^n$. Let $P +Q := \{x+y ~\vert~ x \in P; y \in Q \}$
a) Show that $P + Q$ is a polyhedron.
b) Show that every extreme point of $P + Q$ is the sum of an extreme point of $P$ and an extreme point of $Q$.