Đáp án:
\({D\left( {0;6} \right)}\)
Giải thích các bước giải:
\(\begin{array}{*{20}{l}}
\begin{array}{l}
Ta\,\,co\,\,:\,\,\overrightarrow {AB} = \left( {1; - 1} \right)\\
Goi{\kern 1pt} \,\,D\left( {x;y} \right) \Rightarrow \overrightarrow {DC} = \left( {1 - x\,\,;\,\,5 - y} \right)
\end{array}\\
{ABCD{\kern 1pt} \,\,la\,\,{\kern 1pt} hbh \Leftrightarrow \overrightarrow {AB} = \overrightarrow {DC} }\\
{ \Leftrightarrow \left\{ {\begin{array}{*{20}{l}}
{1 - x = 1}\\
{5 - y = - 1}
\end{array}} \right. \Leftrightarrow \left\{ {\begin{array}{*{20}{l}}
{x = 0}\\
{y = 6}
\end{array}} \right. \Rightarrow D\left( {0;6} \right)}
\end{array}\)
