$$\left. \begin{array} { l } { + 2 h x y + b y ^ { 2 } = 0 } } \\ { \text { L e t t h e t w o l i n e l i n e \right.$$
$\left\{\begin{matrix}x=-\frac{by}{2h}\text{, }&h\neq 0\\x\in \mathrm{C}\text{, }&\left(b=0\text{ and }h=0\right)\text{ or }y=0\end{matrix}\right.$
$\left\{\begin{matrix}x=-\frac{by}{2h}\text{, }&h\neq 0\\x\in \mathrm{R}\text{, }&\left(b=0\text{ and }h=0\right)\text{ or }y=0\end{matrix}\right.$
