Resolução:
Para um ponto $\;P(x;y)\;$, vamos chamar de $\;P_x\;$ e $\;P_y\;$ as projeções do ponto $\,P\,$ respectivamente sobre o eixo das abscissas (x) e sobre o eixo das ordenadas (y).
Resposta:
$\,A(2\,;\,3)\;\;\;\Rightarrow \; \left\{\begin{array}{rcr} A_x\;(2\,;\,0) \phantom{X}& \\ A_y\;(0\,;\,3)\phantom{X}& \\ \end{array} \right.$
$\,B(3\,;\,-1)\;\;\Rightarrow \; \left\{\begin{array}{rcr} B_x\;(3\,;\,0) \phantom{XX}& \\ B_y\;(0\,;\,-1)\phantom{X}& \\ \end{array} \right.$
$\,C(-5\,;\,1)\;\Rightarrow \; \left\{\begin{array}{rcr} C_x\;(-5\,;\,0) \phantom{X}& \\ C_y\;(0\,;\,1)\phantom{XX}& \\ \end{array} \right.$
$\,D(-3\,;\,-2)\;\Rightarrow \; \left\{\begin{array}{rcr} D_x\;(-3\,;\,0) \phantom{X}& \\ D_y\;(0\,;\,-2)\phantom{X}& \\ \end{array} \right.$
$\,E(-5\,;\,-1)\;\Rightarrow \; \left\{\begin{array}{rcr} E_x\;(-5\,;\,0) \phantom{X}& \\ E_y\;(0\,;\,-1)\phantom{X}& \\ \end{array} \right.$
