[latex] \left \{ {{x-2y=3} \atop {5x+y=4}} \right. [/latex]

[latex] \left \{ {{x = 3 + 2y} \atop {5(3 + 2y) + y = 4}} \right. [/latex] [latex] \left \{ {{x = 3 + 2y} \atop {15 + 11y = 4}} \right.[/latex] [latex]\left \{ {{x = 3 + 2y} \atop {11y = -11}} \right.[/latex] [latex]\left \{ {{x = 3 + 2y} \atop {y = -1}} \right.[/latex] [latex]\left \{ {{x = 1} \atop {y = -1}} \right.[/latex]