Question

X2+y=11
x+y=5 помогите!!!!!

Answer 1

$\left \{ {{ x^{2} +y=11} \atop {x+y=5}} \right. \left \{ {{ x^{2} +y=11} \atop {y=5-x}} \right. \left \{ {{ x^{2}+5-x=11} \atop {y=5-x}} \right. \left \{ {{ x^{2} -x-6=0} \atop {y=5-x}} \right. \left \{ {{ \left \{ {{x=3} \atop {y=2}} \right. } \atop { \left \{ {{x=-2} \atop {y=7}} \right. }} \right.$

Корни квадратного уравнения мы нашли по т.Виетта:
b=-(x1+x2)
c=x1x2