Câu hỏi 22

Qua \({V_{\left( {I;2} \right)}}\) biến \(A\left( {1; - 2} \right)\) thành \(A'\left( { - 5;1} \right)\)

\(\begin{array}{l} \Rightarrow \overrightarrow {IA'}  = 2\overrightarrow {IA} \\ \Leftrightarrow \left( { - 5 - x;1 - y} \right) = 2\left( {1 - x; - 2 - y} \right)\\ \Leftrightarrow \left\{ \begin{array}{l} - 5 - x = 2 - 2x\\1 - y =  - 4 - 2y\end{array} \right.\\ \Leftrightarrow \left\{ \begin{array}{l}x = 7\\y =  - 5\end{array} \right. \Rightarrow I\left( {7; - 5} \right)\end{array}\)

Qua \(V\left( {I;2} \right)\) biến \(B\left( {0;1} \right)\) thành \(B'\):

\(\begin{array}{l} \Rightarrow \overrightarrow {IB'}  = 2\overrightarrow {IB} \\ \Leftrightarrow \left( {x - 7;y + 5} \right) = 2\left( { - 7;6} \right)\\ \Leftrightarrow \left\{ \begin{array}{l}x =  - 7\\y = 7\end{array} \right. \Rightarrow B\left( { - 7;7} \right)\end{array}\)

Chọn C.