{4x-y=3,{x-y=6 помогите пожалуйста

[latex] \left \{ {{4x-y=3} \atop {x-y=6}} \right. [/latex] [latex] \left \{ {{y=4x-3} \atop {x-y=6}} \right. [/latex] [latex] \left \{ {{y=4x-3} \atop {x-(4x-3)=6}} \right. [/latex] [latex] \left \{ {{y=4x-3} \atop {-3x-3=0}} \right. [/latex] [latex] \left \{ {{y=4x-3} \atop {x=-1}} \right. [/latex] [latex] \left \{ {{y=-7 } \atop {x=-1}} \right. [/latex] ответ:(-1;-7)