If $G$ is a group, prove that $P_{n} \cong \bigotimes^{n+1} \mathbb{Z} G$, where $P_{n}$ is the $n$th term in the homogeneous resolution $\mathbf{P}(G)$ and
$\bigotimes \mathbb{Z} G=\mathbb{Z} G \otimes_{\mathbb{Z}} \mathbb{Z} G \otimes_{\mathbb{Z}} \cdots \otimes_{\mathbb{Z}} \mathbb{Z} G$
the tensor product of $\mathbb{Z} G$ with itself $n$ times.