Решите систему уравнений методом подстановки: [latex] \left \{ {{y-2x=1} \atop {12x-y=9}} \right. [/latex]

[latex]y = 2x+1\\ 12x - (2x+1) = 9 \\ 10x-1 = 9\\ 10x = 10\\ x=1\\ y = 2\cdot1+1 = 3\\ \\ \left \{ {{x=1} \atop {y=3}} \right. [/latex]

[latex] \left \{ {{y-2x=1} \atop {12x-y=9}} \right. [/latex] [latex] \left \{ {{y=2x+1} \atop {12x-y=9}} \right. [/latex] [latex] \left \{ {{y=2x+1} \atop {12x-(2x+1)=9}} \right. [/latex] [latex] \left \{ {{y=2x+1} \atop {10x-10=0}} \right. [/latex] [latex] \left \{ {{y=2x+1} \atop {x=1}} \right. [/latex] [latex] \left \{ {{y=3} \atop {x=1}} \right. [/latex] Ответ:(1;3)