$$Zn+Z_{2}=(a+bi)(c+di)$$
$\left\{\begin{matrix}Z=-\frac{bd-ac-iad-ibc+Z_{2}}{n}\text{, }&n\neq 0\\Z\in \mathrm{C}\text{, }&Z_{2}=\left(a+ib\right)\left(c+id\right)\text{ and }n=0\end{matrix}\right.$
$Z_{2}=-\left(-\left(a+ib\right)\left(c+id\right)+Zn\right)$
