Розвяжіть систему рівнянь х/3 +у =1 у^2 -ху=7

[latex] \left \{ {{ \frac{x}{3}+y=1 } \atop {y^2-xy=7}} \right. [/latex] [latex] \left \{ {{ x+3y=3 } \atop {y^2-xy=7}} \right. [/latex] [latex] \left \{ {{ x=3-3y } \atop {y^2-xy=7}} \right. [/latex] [latex] \left \{ {{ x=3-3y } \atop {y^2-y(3-3y)=7}} \right. [/latex] [latex] \left \{ {{ x=3-3y } \atop {y^2-3y+3y^2=7}} \right. [/latex] [latex] \left \{ {{ x=3-3y } \atop {4y^2-3y-7=0}} \right. [/latex] [latex]4y^2-3y-7=0[/latex] [latex]D=(-3)^2-4*4*(-7)=121[/latex] [latex]y_1= \frac{3+11}{8} =1.75[/latex] [latex]y_2= \frac{3-11}{8} =-1[/latex] [latex] \left \{ {{y_1=1.75} \atop {x_1=3-3*1.75}} \right. [/latex]   или   [latex] \left \{ {{y_2=-1} \atop {x_2=3-3*(-1)}} \right. [/latex] [latex] \left \{ {{y_1=1.75} \atop {x_1=-2.25}} \right. [/latex]      или   [latex] \left \{ {{y_2=-1} \atop {x_2=6}} \right. [/latex] Ответ: (-2.25; 1.75);  (6; -1)