[tex]\left \{ {{y=x+3} \atop {2x+3y=-1}} \right.[/tex]
[tex]\left \{ {{y=x+3} \atop {2x+3(x+3)=-1}} \right.[/tex]
[tex]\left \{ {{y=x+3} \atop {2x+3x+9=-1}} \right.[/tex]
[tex]\left \{ {{y=x+3} \atop {2x+3x=-1-9}} \right.[/tex]
[tex]\left \{ {{y=x+3} \atop {5x=-10/:5}} \right.[/tex]
[tex]\left \{ {{y=x+3} \atop {x=-2}} \right.[/tex]
[tex]\left \{ {{y=-2+3} \atop {x=-2}} \right.[/tex]
[tex]\left \{ {{y=1} \atop {x=-2}} \right.[/tex]
[tex]\left \{ {{x=-2} \atop {y=1}} \right.[/tex]
