\[\begin{array}{l}
Goi\,\,\,B\left( {a;\,\,b} \right)\\
A = {T_{\overrightarrow v }}\left( B \right)\\
\Rightarrow \left\{ \begin{array}{l}
1 = a + 2\\
4 = b - 3
\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}
a = - 1\\
b = 7
\end{array} \right.\\
\Rightarrow B\left( { - 1;\,\,\,7} \right).
\end{array}\]