Let $V=(-6,\infty)$. For $u,v \in V$ and $a\in{\mathbb R}$ define vector addition by $u \boxplus v := uv + 6(u+v)+30$ and scalar multiplication by $a \boxdot u := (u + 6)^a - 6$. It can be shown that $(V,\boxplus,\boxdot)$ is a vector space over the scalar field $\mathbb R$. Find the following:

the sum:

$0\boxplus -4 =$

the scalar multiple:

$5\boxdot 0 =$

the additive inverse of $0$:

$\boxminus 0=$

the zero vector:

$\underline{0}_V =$

the additive inverse of $x$:

$\boxminus x=$