X+y=9 xy=14 решите систему уравнения

[latex] \left \{ {{x+y=9} \atop {xy=14}} \right. [/latex] x=9-y (9-y)y=14 9y-y^2-14=0 y^2-9y+14=0 D=81-56=25 [latex] y_{1}= \frac{9-5}{2}=2 [/latex] [latex] x_{1}=9-2=7 [/latex] [latex] y_{2}= \frac{9+5}{2}=7 [/latex] [latex] x_{2}=9-7=2 [/latex] Ответ: (7;2), (2;7)