Phương trình tham số của đường thẳng AB là

\(\begin{array}{*{20}{l}}{\left\{ \begin{array}{l}x = - 1 + t\;\\y = 3t\;\\z = t\end{array} \right.}\end{array}\quad (t \in \mathbb{R})\).

\(\begin{array}{*{20}{l}}{\left\{ \begin{array}{l}x = 1 + t\;\\y = 3t\;\\z = 0\end{array} \right.}\end{array}\quad (t \in \mathbb{R})\).

\(\begin{array}{*{20}{l}}{\left\{ \begin{array}{l}x = - 1 - t\;\\y = 3t\;\\z = 0\end{array} \right.}\end{array}\quad (t \in \mathbb{R})\).

\(\begin{array}{*{20}{l}}{\left\{ \begin{array}{l}x = - 1 + t\;\\y = 3t\;\\z = 0\end{array} \right.}\end{array}\quad (t \in \mathbb{R})\).